Opened up my insecurities to my boyfriend

So I opened up to my boyfriend about my body insecurities and how I feel he’s going to leave / cheat on me with another woman. I’ve been told in the last in different ways by different guys that they would not be able to resist temptation if a full bodied woman approached them ( big butt/ big boobs / wide hips. I myself have 34B cups, wide hips, and a flat stomach. My butt is small but it has giggle and is athletic. I do not feel comfortable in my body to say the least and this is due to previous relationships and off hand remarks. I always feel very uncomfortable when I’m In the same room or vicinity of a woman such as this especially when I’m with my boyfriend. This issue came up because my boyfriends social media accounts had been filled with gorgeous woman whom had big amazing butts and the works and I noticed and was freaking out at him because of how it made me feel and my past experiences. I just feel a mess and ashamed because of everything I told him.