I'm sure there were years of me talking about quitting drinking, and failing. Looking back, I failed because I thought sobriety was just a matter of intent. I intended to get sober, therefore I will.
Problem was, addiction cares less about intent.
I can say this though...when I truly wanted to get sober, it was different. I could feel it inside. The last time I said "I quit" I could tell I really meant it. Again, saying it means squat. I had to prove it by my actions, doing what ever it took to stay sober.