I feel like an asshole and I hate it

So my ex fucked me up. We dated for four months and in those four months she and I planned to move in together. Then one day out of the blue she tells me she needs a break and breaks up with me over Snapchat the next day telling me she was never actually attracted to me and she asked me out when she didn’t like me like that because she thought she would develop feelings later on. I know I was naive to get so invested in a relationship so early on but it’s in the past now and now everything she does pisses me off! We have been friends for years and years before we ever dated and after breaking up she wants to pretend we never dated and I can’t do that because I’m so mad at her! It’s like now that we’ve dated I can see all the worst parts of her personality and I can’t believe I was so blind to them for years. And now she has a new boyfriend and it feels like she just went and replaced me with a boy without a second thought when she told me she wasn’t in the place to be in a relationship right now. And I feel like such a dick because I cannot stand her anymore like I don’t even want to talk to her. She’s so childish and her personality is so annoying and I hate that I’m thinking this way

Edit: for people saying remove her from my life, I wish I could but she’s friends with all my friends so it’s not that simple, I keep seeing her on their snap stories and Instagram posts it feels like I can’t escape her