Sad all over again 😧

So I was seeing a guy a couple months ago and he dumped me for his ex. He went on to tell me (idk why this was relevant) that I actually knew her. We went to prom together, took amazing pics, were friends for awhile, then a year later she asked to take me out on a date(she's bi.. and this might have been during their relationship since he told me she cheated on him texting girls inappropriately. She even talked crap in the background while I was trying to talk to him over the phone when this happened). I just saw one of our prom pics together for the first time in forever and it just made me sad. I can't help but to compare myself to her now even though I know I'm beautiful. It just sucks that that memory is ruined for me now. Idk why he even felt the need to tell me who she was because now all I do is think about her with him. It's just ass man. Thought he was perfect. Just ironic that it happened to me 😩😣😣