Despite a lot of the other comments suggesting "easy" fixes, untreated and long-lasting depression (in general) and burnout (specifically) can have these lasting effects. These do NOT seem to be treatable without psychiatric and medical intervention - the brain has spend too much time in a depressive state, and it can't get out of it by itself. Psycho therapy alone and other usual interventions (sleep, proper nutrition, positive stimulation) simply won't help anymore.
So, advise for everyone: real (in terms of "professionally diagnosed") depression and burnout for too long (over months and years) can break you in ways you can't imagine. Treat it early.
I'd argue it's a game of chance. You already mentioned a lot of things necessary to "build" a friendship, but I dislike the word "building". While there certainly are mistakes you can do, friendships are usually not "build" - maybe some work needs to be put in to be "maintained" in the long run.
Genuine friendship comes with shared interests (which is why it's easier to find friends in common activities that you are genuinely interested in), but also the simple chance of meeting interesting people. The best predictor of friendships in student dorms seems to be the relative distance of their rooms - see Kurzgesagt's "Why You Are Lonely and How to Make Friends" at https://youtu.be/I9hJ_Rux9y0 for some more interesting facts.
It's completely normal to have different level of friends - some to party with, some to nerd around certain topics with, some to have deep meaningful talks but you only can stand a meeting once a quarter... And you are only able to actively maintain a certain number of friendships.
I found that I don't have nearly as many "friends" as many of my peers have (being a 40-something doesn't help much either), but the friends I got are rock solid. They are kinda lopsided because I'm offering too much help most of the time without accepting much help from them - that's what I need to work on.
I bill everything, that I do for a client, on the clients premises, or that I feel like it's work - specifically if the client asks me to attend something. I draw the line when it's my benefit only (e.g. going out with the coworkers for a beer after hours). But beside that: If I don't get a problem I was working on out of my head and research it for 2h at 3 in the morning, I bill it.
I do not sign any contracts, which automatically cut my workday to 8h (because they are illegal in my jurisdiction). If I work more than 8h, I sometimes get into trouble with some tight-assed legal department and I then just shift my hours on the timesheet around, until it fits.
You should not under any circumstances reduce your rate, if you feel like the rate reflects your skill. Instead, explain your rate with your achievements, references, etc. and negotiate the gain/speed/performance your client is getting by hiring you with your higher rate instead of a competitor.
I recommend against daily rates if you are able to zone into work and get serious shit done in 12h-shifts, while other days are just "eh" and you go for a jog after 4h. Usually, everyone notices your 4h-days while ignoring your 12h-days.
If you trust your skills and your ability to define the scope of a project well, consider going into milestone-based payment (never for a whole project!). This might be more lucrative for you in the long run.
If you choose this, think about a timespan you're willing to work without payment and half that timespan - that's the number of days between milestones you'll define. Should you hit a bad client, you'll stop working if payment hasn't gone through for the past milestone for whatever reason and when you're reaching the second milestone - never accept apologies, process delays, "those pesky policies"; you work for payment, everything else is the clients' problem, not yours.
My wife had a ~6month long affair, after ~15 years together. While we were core renovating our just bought home and despite having three kids. I found out the hard way, not because she confessed it openly. We had no money problems (due to my work), we always talked about everything. Life was somewhat stressful (due to the house renovation in addition to my full job and kids) but fine. I had developed feelings for a friend once, talked about it with my wife, she wanted to stay monogamous. She didn't return that behavior years later with her affair.
In counseling and long talks, we found that I could not have done anything different. She's sorry. And while I often think of leaving her, I won't break up the family for my kids - still seems like the best option, ~2 years later (if I take their mental health into account and am not only considering myself).
It's a cliché, but "knowing" things and "living through" things are very, very different:
* Never give yourself up in a relationship or a job
* Never risk everything you have (I couldn't divorce her even if I wanted, without having to pay exorbitant monthly payments)
* You can do everything right and it still can go wrong
* Just because you give everything doesn't mean others will behave the same towards you
"Knowing" these things is different than "living through" them. The affair broke my mental model of the world as a whole. I thought: no matter how bad it is, I can influence my very tiny happy bubble in a distopian world, and giving everything to the right people (who also give a lot back) will make them honor our common code of behavior.
Now, I trust a lot less. I don't waste time on relationships I don't get as much out as I put in (no matter if acquaintances, friends or business related), I secure myself a lot more (prenup, letters-of-intends, etc.).
I'm still miles away of not being depressed and feeling broken, or being able to concentrate or being creative again (which means I'm still unable to work effectively for more than a few hours a day). And the model of the world I have in my head now does not feel like something I want to live in, but it's still - slowly but steadily - changing for the better. Getting here took an enormous amount of effort: Being unable to work at all for about a year, being physically unable to stand, just breaking down in public or in front of clients, amnesia (there are weeks of my life I simply can't remember, whole vacations during the depression that are just gone). It took psycho-therapy, clinical stays, (re)learning habits and techniques to get me out of bad places...
This is not a call for sympathy, but please do learn from me (I made a throwaway account to keep my anonymity).
TLDR: My point is:
* Take care of yourself and don't trust others unbounded. Ensure the "what ifs" don't cost you too much (e.g. prenup, letters-of-intend, ...).
* Happiness is a choice for the most part. Enjoy life and the moment while you can. Sometimes it's little things, sometimes it's big things. But notice them as much as you can.
* There's different levels of honesty - think good about which one you choose. Honesty leads to vulnerability and some people will misuse it.
* Stay positive and give first in relationships, but always listen cautiously to your gut - if it tells you that you are giving too much and receiving too little, reconsider and react. fast.
* Keep friendships and hobbies you enjoy alive - despite family, job and relationship. Friendships are built on common experiences (not common interests!), and the older you get, the less chances for new common experiences with new people you'll have. Hobbies and things you enjoy are as important. If shit hits the fan hard, friends and having routines to recharge your battery are the things that can save your life and get you out of the hole.
While that is an absolute possibility, the statistics give that outcome a much lesser chance than fucking up the children in one way or another. Nice to hear it went for the better for you! :)
So far, we manage quite well - although my children obviously know something's wrong with me and we talked about my depression symptoms (without telling them the reason), we manage to keep our kids out of our problems.
Your story is quite messed up, your partner is responsible for ruining your trust and your wellbeing. And it seems to me that this one time slip up for 6 months is something that is no accident but says something fundamental about your partner. Not sure what you could do now and you’re right about being depressed about it. But life throws you a curveball and things may end up in a totally different unexpected place and it could totally turn out for the better, you never know. Also, learn to be a bit selfish and love yourself some more.
Everyone's story is different. What op is doing might be right for op. Or maybe not. But as the child of divorcees whose divorce massively improved my relationship with both of them I thought it might be helpful perspective.
Sure, I hear you but not all cases of divorcees end up well for the children. When both parents end up fullfilled post marriage and manage to move over the financial hurdles the kids are better off with separated/divorced but happy parents, however that’s not always the case. And nowadays a divorce can severely handicap one of the parents in a financial way so not divorcing has quite a lot of incentive. Of course being miserable in the marriage just for the sake of the kids probably doesn’t end up too well either, ideally the best outcome is to move on with life.
So, advise for everyone: real (in terms of "professionally diagnosed") depression and burnout for too long (over months and years) can break you in ways you can't imagine. Treat it early.