How to get over a guy I never dated. need help asap

so there was a guy who I was close with since middle school, I’m a freshman in college now. we dated in 7th grade, stayed friends, then around junior year started being super attracted to one another. We had sex a few times and then he left me for this girl who had just moved here. they started dating then I dated someone else. both of our relationships were terrible and when we were both on breaks with these people we hooked up again. I felt a real connection this time like real as can be. and we hungout a bunch of times then we both got back with these bad people we were dating bc it was Christmas time. and then I broke up with my bf and he stayed w his gf for a while like 6 months and I’ve recently started thinking about it again because they broke up and he still hasn’t texted me. the last time we spoke his gf made him send me a message that was like “I don’t want you” and now he’s talking to some girl and im left sad and lonely and missing him so much. I want to text him but I can’t. I don’t know what to do. the cold season brings warm memories of him.