I love my ex, and I want him back permanently

I appreciate your advice very much. It’s hard for me still to understand how someone could stop caring so fast but i do need to stop thinking about it. I told him my values before we started and he agreed to all of it. No sex before marriage was also one of his he said. And he said many times it’s not because of sex. I’m just so busy and i wanted him in my life so every promise be made i didn’t have a time for second thoughts.
Anyways The thing is for so long everything i did was for him and now it’s so hard to do things for myself. I only wanted to move out from my parents house to be with him and that’s what was driving me to work hard in school and do well in interviews. He was my rock. When everything failed he was there. At least i thought he was. I didn’t know about the lying abd cheating back then. Now everything is failing and he isn’t there. I don’t know how to fix my life. The pain is becoming better but Idk how to stop loving him. How do i let him go? How do i heal?
I’ve tried everything and nothing is working. I’m going counseling next week.i hope it helps me.