Am I being compared?

Sometimes i wonder if he compares me to other girls, while me and him are doing stuff. I hate the thought that he has done 'stuff ' with other girls. I always think " Am i good enough?", "Am i better than the other girls to him?". Now i have trust problems because of yesterday. I wish i didn't but it's just the way it is. It's like a competition everyday. Challenging myself to do things. I get afraid that he will leave me if i don't do the things that he likes. I want to be way better than his ex girlfriends. It would kill me if he thought of other girls while he was with me. It would be emotional cheating. Well it depends on how he thinks of them. Maybe I'm just over thinking again.

But then again i see myself as the upgrade. I am better than them. He wouldn't be with me if I wasn't.