Now, I find myself to be a pretty darn introverted mofo internally (I line up perfectly as a full-out INTP on the Myers-Briggs scale if that means anything to anybody), but I've found that socializing is just as useful of a skill as programming or playing a musical instrument. Sure, I find it to be significantly more tiring than either of those two activities, and I'm not nearly as proficient at it as I'd like to be, but it is a skill -- not some distant genetic trait that you might be hopeless to turn on -- therefore, it can be at least somewhat learned. The issue then is just about wanting to learn it.

I'm not about to be condescending about it and suggest something along the lines of "if you really cared/wanted it bad enough... blah blah blah", because I find statements like that to be annoying and unhelpful. I merely wish to bring awareness. Learning is a skill, and equivalently but more to the point: learning how to learn any specific skill, is a skill. It is OK to be inexperienced in this area, we all start off this way; it is merely being aware of this situation that seems to set mindsets apart. This inability to learn a skill that involves "looking like an idiot" as part of the learning process, signals inexperience with learning skills that require noticeable/major discomfort to acquire. And again, that is OK -- it makes total sense. The thing to realize is, that is all it is: discomfort. It's not really 'dangerous' regardless of how much it feels that way, it's just as benign (and possibly as annoying to some people) as developing callusus on your fingers to play guitar. It's a bit of a painful process, and you really can't get into the 'flow' of playing for extended periods of time until you develop them, which requires building up the calluses in baby steps; because otherwise you'd just be cutting up and burning your fingers up trying to go any longer. So if it helps at all, just look at it as building up 'social calluses'. It'll hurt, yeah, I acknowledge that. But hey, that's what's involved if you wan't to learn how to play. I mean, You might prefer to learn other instruments like piano because they doesn't involve this painful step, and you might get pretty darn good at pickup up those other instruments, but at the end of the day, you still wouldn't have learned how to play the guitar.

As for the depression, I've been completely and deeply suicidal many a time in my short life (used to be an annual tradition practically), and I really can't give you a quick answer for it unfortunately. The best thing I found is to just keep busy, but you seem to have discovered that strategy on your own already, so kudos! I know it took me a while... I believe there are many reliable findings about meditation reducing depression+anxiety (possibly as a result of its regenerative abilities with regards to 'willpower'), but meditation is really just an intense exercise in attention. And attention I believe, has also been found to invoke a state of anxiolytic relaxation. Therefore, keeping busy makes sense as an anti-depressive mechanism. I wish I could produce some sources on this, but I'm already procrastinating quite badly on a paper I need to have done in about an hour, I just felt I needed to leave a response here before I forgot. Hopefully I was able to help.