I understand your position Loki. I’ve been there. Well I truly think I’ll always be there to be honest.
Depression is a daily fight. You have acknowledged already that you have issues and need help. That is the first step. I encourage you to go to the doctor.
I had this low self esteem as well, and it make life quite harder than it is. It took me a big while to recognize it and get help. First, it felt like a liberation. Talk to someone without being judged felt really good. It didn’t solve all my problems but was the start of a new stage in my life.
Step by step I recovered old friendships, make new ones, lost others, but I’m still going.
Now I’m close to my 40s and I know myself way better to a point that I detect the bad thoughts on time, because they will not stop, and control them, make peace with myself, even have a laugh at me and keep going with my head up.
About the game, it was tough. I tended to blame myself for everything. Although the more I learnt about the game, about everyone 's role, this was disappearing as well. I can recognize when it’s my fault and when it wasn’t. I don’t need to point fingers at anyone either, because, what’s the point, next game I will probably play with different people so I’m not going to solve anything.
Only productive criticism for the team, like, we need to focus more on protecting our supports or cover the flanks, play more safe, not in the middle of the map, etc.
If you find people difficult, start by leaving voice chat and /hidechat. (Command for hiding chat). Don’t even check people’s names. For me there is only “ana”, “genji” etc. With time, you 'll find out that you can even be the person who makes the calls and carry your team to wining (although I only do this while playing tank)
Focus on your own performance, don’t bother If you lose or win, although is very nice to win of course. But not important. The most important thing for you right now is start believing in yourself.
There is an exit to this, there is light. I promise. If I did it, everyone can. I believe in you.