how to get over a relationship?

I've always struggled when it came to dating, I have very high standards that are pretty hard to meet apparently and i've met this guy when I was 13-14, he was 18 at the time and we started talking and we dated and broke up multiple times and it was always me coming back, last year he blocked me and I didn't think much of it but now i'm thinking about him again, i made my friend add him but he blocked them and i just can't seem to get over him