Tired of trying to be happy. I wanna give up.?

I'm 17 years old.My mother is and has been since my birth and addict, of almost everything.Beer, crack, pot, cigarettes, sometimes meth if anyone has any.If it's a drug, she wants it. My Dads much the same but he tries to overcome it.Finally, about half a year ago,me and my Dad moved out.It's just me and him now.Things are even worse at my moms house,but things aren't so great over here either.He keeps relapsing.I have no car or lisence yet,so have to depend on him,and he's very undependable for rides.So I've given up on trying to keep and maintain friends or anything for that matter,I can't.Their parents get tired of giving me rides and they get tired of me having to cancel plans because Dad got to my money or disappeared,sometimes not to reappear for days.I got fired from volunteering because I was too undependable.I'm so tired of trying.I spend all day,every day,in front of the computer,trying to lose myself and forget life.I don't know what to do anymore but say..help?