Breakup

My ex and i broke up a month ago. It wasn't one of us that did, it was both of us. And the reason was: we didn't have time for each other. We never really fought or something like that, and we really liked each other. But we weren't talking regularly and we could only go out one day of the week. Things got... boring, and we were feeling distant, so we broke up and blocked each other, but we gave it a month to unblock ourselves, and now that this month has passed, i didn't unblock him because my history teacher that is also his teache said he saw him going out with a girl. I don't know if i should unblock him, but i kinda want to because i miss him. I don't miss having him as a boyfriend, i miss having him as a friend. He is the only one that really understands me, and everything i do i remember him. What should i do??