I am about to give you the loving advice you need:
Fuck that shit.
You asked for help. You got excellent advice from many people here. Then you came up with excuses for not taking that advice.
Forget "social stigma". Forget the past. Forget your perceived weaknesses. Forget your excuses.
You are obviously smart and want to help yourself, otherwise you wouldn't have posted here to begin with. You need someone qualified to talk to (in person, not here). Do it and recapture your life.
Things are never as bad as they seem when you're at a low point. You will soon discover that once you take action. Do it now. Best wishes.
you really have to just bite the bullet and go talk to a shrink. I had some hang-ups about this initially, but afterwards I realized the outside perspective was so helpful that I was a fool not to have done it earlier.
I think you might have a bit of anxiety. the way you describe any negative thought or memory pulling you back down reminds me a lot of myself. the good news is that there are lots of strategies for dealing with anxiety, and a shrink can help point you in the right direction. hack your brain!
I think everybody goes through that. It seems like such a big deal to go to a shrink. Once you go, you realize everyone has issues, it's not really a big deal.
In mine too -- possibly not as great as yours, but there's quite a lot of people, even in theoretically well-educated workplaces.
I have visited a psychiatrists with my problems anyway, and it definitely helped. Also, most of my friends know about that and I never had any problems, but that's probably thanks to my choice of friends. If you pick carefully you should have no problem.
Think about it like that -- visiting a shrink might cause your some problems, if it gets known in wrong places, and hopefully you can move elsewhere when that happens -- a harsh solution, definitely painful, but usually not the end of the world.
Your current condition definitely causes problems for you right now. Also, you can't just move away from your current problems.
Think of a shrink as a better version of what you've already done in asking for help. He's an pretty smart guy(hopefully) who you can tell shit to that you would never tell anyone else. And he'll give you an honest 3rd party perspective, which is exactly what you need. You need someone to tell you that it's not as bad as you think it is. You need someone to tell you that the way you are seeing yourself is complete bullshit. You need someone to help you figure out what actions are going to make you start feeling good about yourself and encouraging you to do them.
You need to see a psychiatrist. Your symptoms sound a lot like real depression. It's possible that it will get better on it's own and you'll make some new friends and see the bright side of life, but it's just as likely you'll get worse. Depression is a brain chemistry problem that makes it almost impossible for your brain to process reward and pleasure. I know people who have thrown big chunks of their lives away by not seeking help. Please don't be one of them.