I think my friend stole money from me but I can’t prove it, what to do now?

I(21F) really feel so sick to my stomach right now. I love him. But I can’t quite trust him and that’s what sucks. He’ll seem so genuine but then he’s messed up before in the past so I can’t trust him. This guy has issues but he’s always seemed like a genuinely good person. That’s why I’ve never given up.

We were out having food and I said I needed to go use the bathroom and he asked me if I could unlock my car while I do that so he could go get something out of it. He had left his cigarettes in there. But I just have a bad feeling he took something else out of my car, and I have a bad feeling it was money. If it was money, it was likely only a few dollars at most. But maybe I’m overthinking it and he didn’t take anything. What do I do? If I confront him about it he might not tell me the truth. Maybe I should try setting him up to see if he’ll steal again?