You are being self destructive for a reason, find that reason and start working on it.
Drugs and alcohol are not answers they are ways to run away from facing what needs to be faced.
I would recommend you look into some self help stuff.
Holosynch by Centerpointe
Steve G. Jones
Dain Heer - Access Conciousness
There are lots of amazing things out there to help get over all sorts of problems, take the desire to change and use it to help you survive, in many ways you're fighting for your life and we should all hold onto our lives as long as possible.