Uncertainty

I'm a 19-year-old male in a relationship with another 19-year-old male, and we’ve been together for about two months. Since we started dating, I’ve been struggling with insecurities and getting upset over things that shouldn’t matter. This is my first relationship, and my partner has more sexual experience than I do; he was also in a relationship before me, which might contribute to my feelings, though I’m not entirely sure. Even though his past relationship was toxic and he often tells me how much happier he is with me, I find myself feeling down about random comments he makes. For example, during a recent night out, he mentioned a building where he had a certain intimate experience with his ex. This completely unsettled me, and I found it hard to enjoy the rest of the night and felt off for a couple of days afterward. Additionally, I often feel physically insecure, thinking I’m not as attractive as he is, or that he has a better life with a more supportive family and friends. I really dislike feeling jealous because I know it’s irrational; he clearly has strong feelings for me and does everything he can to spend time with me. We have good communication, and I genuinely enjoy being with him, but I sometimes experience bad days where I overthink and feel inadequate, making me want to distance myself from him, which is a distressing feeling. Does anyone have advice on how to handle this?