Can’t stop comparing myself to my (22f) boyfriend’s (24m) ex

My boyfriend and I have been together for 2.5 years. About a month ago, I found out he still had hundreds of pictures (including dozens of nudes) of his ex and I was extremely hurt by this. We talked about it and he eventually deleted the photos, but I was left borderline traumatized by what I saw.

Basically, I saw that she had a lot of what I’ve always wanted with him and that she is objectively more attractive than I am. She was more integrated with his family, he was more willing to take pictures of/with her, and he seemed way more proud to be with her.

He told me they broke up because she cheated on him and I also found out that wasn’t true. Their break up was his fault and he was clearly in distress and upset when he told me about it. To my knowledge, they dated for a little over a year.

Until the incident with the photos, I never really thought much about her, but since then it’s the only thing that I can think about. It doesn’t help that he probably gave me way more information about their relationship and breakup than I probably needed. Every time I do something, I think of how she would do it differently. It’s the holiday season, and I think about how less than a year into their relationship, his mom handmade her a blanket and I’m going on my 3rd Christmas with him and she’s never even wished me a “merry christmas”. I just feel bad and like I’ll never fill the void she left when they broke up.

It also doesn't help when my instagram account is public and though I've never met his ex/don't follow her, she clearly knows who I am somehow because I've caught her viewing my story several times.

I guess I'm just wondering how I can stop feeling so insecure. I'm at my breaking point now where if I can't figure this out, I will have to break up with him.