I can’t seem to get over him

I was with my ex for two years and I have mixed feelings about it. Days it would be amazing and there was other days where all we would do is fight, I’m only 17 and I know ill have a lot more boyfriends before I find the right one but I guess I always wished it was him. He left me for someone else and I have accepted it but I just can’t believe he’d do that to me, he treats his new girlfriend with so much more respect then me and it just hurts me. There’s days where I’d never think of him and then I’d breakdown over him, he was also my best friend and knowing we’ll never be the same again hurts me, I watched him grow up and knowing I’ll never see him or even his family again will kill me, I know I’ll see them around maybe, but not being as close hurts. I don’t even feel myself, my family and friends told me I’ve been happier but I don’t feel it, I just want him back.