Welcome to the forums, and keep posting.
I second the above advice. Get to some meetings is my best advice. Get involved, buy the books, read the literature, get a sponsor, start working the steps and the recovery program suggested to you in the rooms of AA/NA. And most of all, be willing to listen and take advice. If you had the answers, if you knew how to 'live clean', you'd already be doing it.
And don't beat yourself up. There's a reason it's called addiction, it means you've lost the power to choose. Doesn't make you a bad person, it's just that drugs are more powerful than we mortals are.