Jesus christ, what's up with the tone of responses in this thread? The kid's 19 year old for fucks sake, he's had a major bad experience, he's going through one of many rough periods of his life so the least you could do is spare him the holier-than-thou attitude that some of you have offered to him.
Collins, now you listen to me, kid. Stay away from drugs from now on. You aren't the kind of person thats cut out for them. Quit drinking alcohol, continue excercising and start eating healthy and vitamin C and E rich food.
Unlike some others, i dont think your situation particularly neccessates medical attention. You probably have anxiety and manic thoughts, that decided to ascribe every possible physical health condition towards this bad experience.
You can see a doctor and preform some tests, if thats going to make you sleep better, depression and anxiety usually disappear with a correct and healthy lifestyle though. I'd wait with the doctors and healthcare.bullsh. if things really dont improve after several months.
Good luck.