I can't stop thinking about my ex... it's stressing me out

So I know once a dude does you wrong and you break it off you should have any communication with them but I couldn't handle it and I kept giving in communication wise and intimately. But now I really think it's over and I want it to be BUT I can't stop thinking about him. I want him to text me and apologize or ask to see etc but he's not and it's stressing me out bad. I don't cry over him anymore but it is making me sad a little and I think I'm breaking out because I'm so stressed. Has anyone been through this. I need some advice