Trust issues

I have major trust issues. The only person I really trust is myself. I'm talking to someone at the moment who lives in another country but I just have a problem believing what he says. In the past I've trusted people and it's bit me in the ass so I just always question people's motives. This guy makes me laugh and makes me feeling pretty hot too considering our conversations and I've been pretty upfront with him about a few things (my insecurities, etc) and he said I'm the only one he wants to talk to. I constantly question this and think he's probably talking to other girls but then I wonder why would he bother with me because it's not like I'm sending him nudes or we're not sleeping together. 😔