If I could just add this: 15 is, for a lot of people, one of the worst ages possible. Even under the best of circumstances, a teen's brain is not finished maturing until as late the early 20's. That can make teens have a tendency to feel depressed, and it can contribute to some teens not always understanding other people's motives very well.
It isn't a matter of the "real world" getting any better. It's more a matter of you getting just a little older, having a little more freedom, being more in charge of your own life, and generally feeling a little more in control of things. Your "real world" can, at least in a lot of ways, be what you decide it to be; but you're not quite old to have quite found your direction (and even "whole self") yet. Don't just the world or life through your 15-year-old eyes. Again, that's a really bad age for most people; and if you had "issues" already, it will be particularly difficult.