How do you let go of someone you know you just aren’t meant to be with?

I still think about my ex and our possible future. I fantasize that we’ll be together again and that this time it’ll be perfect. We’ll spend a lot of time with each other and fall in love all over again. Idk why I still think that way. We’ve been over and done with for years now and I know he’s not the right guy for me anymore. But for some reason, there’s this big part of me that still has this little ounce of hope. It’s enough hope to drive me insane! It’s such a conflicted feeling too! I think it’s my heart that wants all this to happen again while my head knows better enough to just let it all go. He called me the other day. And he was doing that laugh! That cute laugh! That sexy fckn voice! Yeah… I got off the phone real quick! LOL. Ugh! I don’t want to feel this way! I’ve made it this far without thinking about it! And then yesterday he webcams with me and tells me to rate his body! WTF! Who does that?! I was looking at him all disappointed.. Disappointed that he was my first love and that he wasn’t going to be my last. Is it really over if we’re still involved in each others lives? What am I even saying. We’re not really involved in each other’s lives anyways.. We just talk about music and sex and whatever he wants to talk about. We never talk about me or what I have to say. But it’s okay.. Cus then that makes me not want to go to him for anything. I can’t talk to him. He won’t listen. He doesn’t care. I want him to.. But oh well. I just really want to get over him 100000%! I can’t be doing this anymore. I can’t be dreaming about our future that’s never going to happen. I know he’s never gonna love me the way that he did. We were kids back then. We’re adults now.. As much as I hate to say it, we’re going to grow even further apart. And we will be with other people whether we’ll like it or not.. Thats life for ya. I just don’t want to be caught up in this. I NEED TO LET GO! Before I’m stuck like this forever…