I too work in IT industry, I write programs for the past 15 years...but I'm the opposite I don't let ANYTHING put me down. It's all in your head brother. Over the years, I've worked for many corporate america companies and I do agree that most times the job can be extremely stressful but I can assure you, it's all about how you approach the problem. As far as hair, since you said that you have been to hair loss sites for the past few years, you probably gathered enough evidence to suggest that you can get that fixed (of course I don't really know what your NW level is).
You work out - THAT'S GREAT. Keep it up. As far as friends, don't be afraid to get social with people, I know it's hard but instead of saying "I CAN'T" say "I'm currently struggling with", live you life to the fullest, it is VERY SHORT.
Sorry for the lecture, just my $0.02