Keep trusting God. you try to play out in your mind how you're going to quit, and how hard it'll be, but you're usually way off with your expectations of how you need to go about it and how it'll go. God will do it in ways you never thought of. He just needs you to do what he says.
When you start obeying, and deep down you know how, then things will get so much clearer. You'll feel his love more and you'll be like "WOW. I shoulda smartened up sooner, I wasted so much time!" That was me not long ago, and I keep saying things like that. God and this glory just becomes more and more real the more I let Him do his thing in my life. Die of yourself man, you won't regret it!
And if you haven't done anything REALLY stupid yet, get out of that lifestyle before you do. The hardest thing in my life to deal with right now, by FAR, is something caused by the whole drinking and partying lifestyle. If I was without that I feel it'd be heaven compared to this. I will never tell you what it is, but man, let God take you under his wing and protect you from those things so you don't have to go through the pain. I say this out of love for you as a brother. God knows what bad could happen to you at any time, and he wants to get you out of the way of this harm. Let him.
Christ gives complete strangers to you, like us, the compassion to care about you even though we don't really know you. He can do all things and the power of prayer is being fielded (used) through your brothers and sisters here. But actually in a way, spiritually, we know you more than some people who have met you. Because you have confessed things to us. And you better believe the Spirit is much more important than the flesh.
God Bless