I experienced a tremendous amount of depression and anxiety when i was around 20-21 yrs old and was consumed with self-hate, rage, confusion, sadness, and an overwhelming sense of numbness. I would go out in the middle of the night and wander around without any fear and drink all day long (i was going to a community college at the time but would attend my classes wasted because i would drink all day long due to the demons i was dealing with, drinking from a concealed bottle. Miraculously, and i dont know how i survived doing this for two years, but i did well enough to transfer into a good university). Though the depression didnt disappear right away, and i fought with it for another 8-9 years, eventually it started getting less severe about 3-5 years ago. Meditation helps me alot to overcome it.
When i first started getting my bad depression in my early 20's I didnt know what the hell was happening to me. I thought i was possessed, seriously. It was crazy. Its like one day i was normal, then the next day i wasn't..though i had memories of what my "normal days" were like. It took me years to fight through this and to this day i have no idea why i experienced it. I was also getting really bad "night terrors", where something presses on your chest while you sleep. Not sure why i had them but I suspect my brain was dealing with high levels of stress and anxiety? Not sure.
Anyway, not to get off the beaten path...Since then, things are much better. But I know what its like to feel like you're in Hell wishing for death. I was there for a number of years and fought through it alone and its one of the worst feelings to experience. I was able to come through by my refusal to give up. I would fight with everything i had, every day, despite what obstacles i'd have to fight through.
As for what i feel i gained by going through those horrible times..aside from making me a stronger person, it made me much more compassionate towards other people's pain and tribulations. So, with that said, I hope I can help you pull through whatever you're dealing with.
I was able to make it through but I certainly dont tell you this to impress you...but instead to impress upon you the fact that things can get better with time and by remaining strong. You also have the support of alot of ppl here from the looks of it. Hang in there man!