I totally relate to your situation and how you're feeling.
Don't give up just yet.
I'm 31yr, alcoholic/heroin addict, and I'm thinking "where'd my 20s go..?"
You keep trying and if you fall back, you try again. Despite the fact that my first rehab was six years ago and I just kicked heroin two weeks ago, I can say that AA/rehab/soberliving saved my life numerous times.
It absolutely matters that you keep trying.