Whenever I have a craving to drink or do drugs I think about how miserable and what a mess I was at my worst, what I was about to lose (my job was hanging by a thread, for one), and how it'll be exactly the same way, and probably worse, if I go back to it. It's a pretty strong deterrent for me.
When I quit, my dad gave me a good mantra to tell myself if I thought about drinking again: "It's not important." Because really, what is it going to do for me? Aside from likely ruin everything that
is important to me?
The stuff that you're uncovering in therapy, although very painful, will not kill you. The drugs probably will.
I hope you come through this even better than you were before.