Ben, the best advice I can give you is to crawl into a hole for a month or two and don't drink ANY alcohol or hang out with ANYONE who is drinking and smoking - period. If I would have had an event right after I quit smoking, there is no way I could have quit.
I quit on December 28th, two years ago. My first event wasn't until March and that whole time I didn't go anywhere or do anything. I concentrated on quitting. If you need someone to hang out with who isn't drinking or smoking, you know I'll come over and chill. It won't be as much fun as usual, but hey, what are friends for.