Are you a person who can't understand why some people don't like you?

I struggle to understand why anyone would like me. When someone is nice to me, my immediate reaction is that they are just playing me. I am 22 and still haven't had a real romantic relationship because I genuinely believe that no girl would ever want to be me and the phrase "lucky lady" throws me for a loop because I believe I'm miserable to be near. I recently adopted a cat who loves to follow me everywhere and sit on my lap, and I still struggle to accept that she wants to be near me. I do seem to be healing, but I am on a VERY long road to recovery.