Advice on getting over it?

*Long story*

My boyfriend and I of two years broke up in November 2019. It’s been about 3 months and I’m still thinking and dreaming about him. I see people who look like him while I’m driving and at work. I am constantly reminded of him by the little things we used to do together. A little backstory, I was 17 when we met and he was freshly 19. Being almost 21 now, I feel like I “grew up” with him. I matured with him. We moved in together, shared a car, etc. All I’m saying is, I really loved him. Not like anyone before. Things happen and 3 months after we separate, we’re on good terms (neutral, really), but he already has a new girlfriend. I was at peace with it until she messaged me about two weeks ago and had some very unkind things to say. She told me she basically has him now forever and I’ll never see him or hear from him. I lashed out in the heat of the moment and I regret it because now my ex and his girlfriend are blocked on every social media. I really do feel like I’ll never hear from him again and just when I start to come to terms with it, I will dream about him and wake up crying or I’ll “see” him walking on the sidewalk or in a store. This shit sounds so cliché but it’s really happening to me and I can’t stand it. I tell myself I don’t want him back. We weren’t exactly a picture perfect relationship and there were many times we argued/separated briefly. Honestly, he wasn’t really capable of giving me what I wanted at the time but I can’t help but wonder about the future and if I’ll get another chance to build our relationship on more healthy terms, or if his new girlfriend is right, and I’ll never see him again. Thanks to anyone who read this all the way through. Even if this gets no responses, it feels good to vent a little. If you do have some advice on getting over someone you devoted yourself to, please, help a girl out. x