i already make music, thats what i want to do with my life
it doesnt really make me feel better, although i do feel like i have a reason for my existence
Then dig deep. It may not make you feel better, but if you work on your music as much as you can, you can solidify your reason for existence. It's a small window of opportunity that's realistically within your grasp. Also realize that your songs are things that you made on your own, with your hands (so to speak), purely out of you, and look at the results. Amazing pieces damn close to outright professional works. You definitely have more than "nothing", you have a knack many of us, including myself, wish they had.
Happiness comes when things work out for you, and obviously they haven't. There's nothing wrong with that. You're a living, breathing human being just like the rest of us, and what you're feeling is
completely understandable given what you've had to put up with. That's a good sign, because it means
you know your mother's insane,
you had the initiative to get away from it all, and even if you haven't been entirely successful so far (though nothing ever works out exactly as we want), you've also had the initiative to try to make a better life for yourself. You're already taking all the right steps in making your life better.
What you've been doing shows me above all that you're a
normal, sane person. You're not some random piss-soaked drug addict rambling hobo who's so disconnected from reality he can't even see how far he's fallen. You're still grounded in reality as a sane human being. I look at you on your Youtube channel and I don't see a freak, I simply see a person who's been through a lot and understandably expresses that. You're still very young, at 21, and you've an amazing talent. Forget about what you THINK is in the future, because you know you think there's nothing in store for you. Fuck the "future". Take your talent, throw caution to the wind, and see where it takes you. You've got nothing to lose.