Pleasure problems

Okay so I've only done sexual stuff with my ex but nothing ever felt good. He was my first and I was his so I thought maybe it was just because we were new at it but nothing changed throughout our relationship. It didn't hurt or anything but it didn't feel like anything ever. I'm already insecure about my body so I don't think I could just invite any guy in again but now I'm scared I won't ever feel anything with any guy. What's wrong?