Stephanie--I think you're disturbed. I lived with my ex for two years, have lived with men before, and I have NEVER gone through their wallets, no matter how much I was jumping off the walls in distrust.
Bonbon--why wonder if he's got a drug problem? Or a drinking problem? Who cares? He's obviously got a respect problem. My purse is boring enough for my nieces to crawl over and rip it apart but they're the only ones allowed to touch it. In a way, it's my heart. I'd rather a guy lift a $20 off my table than go through my purse.
You don't have to confront him. Just don't see him again. Just my opinion.
You do have my sympathy, I'd be throwing things in anger and frustration if I was in your shoes right now.