What does this mean? Or am I overthinking?

My husband opened up to me about his ex and their problems. He said something about being in jail for a night once and I asked if it had to do with her so he went on to tell me the story. Then I asked if that’s why they broke up and as he was telling me about it he kind of spaced out. His eyes were just focused on the wall and he went blank.

I got a little upset cause i thought he was like thinking about their relationship and idk why I have such a big problem with that.

Does anyone else have this fear that they loved their ex more than they love you? Like what if he misses her or what if she was better? He told me she would make little things for him like sweets and letters and I don’t do any of that but we’re married and have a baby.

I always wonder what if the sex was better. What if what if. How do I stop and why the heck am I so worried.

Our whole marriage I’ve been pregnant/ postpartum now I’m pregnant again so I’m not very mobile during sex or anything like that. Play we don’t have our own place so I can’t even really be the wife I want to be.