Can someone give me this advice

Idk how to let my ex go. He says he still wants to see if we can maybe work it out and he wants to try and love me again but he won’t ever truly, we broke up after dating for three years, five months later he said he loved me and then dumped me two days later because he said it “went away”. I’ve blocked him multiple times and still come back to be “his friend”. I have no one else besides him to talk to. No friends at the moment. I’m 17 btw and I’ll starts school in three weeks. By then I’ll be okay with blocking him but now it’s just so hard to let go because he’s the only person I have.

I don’t know how to not come back after blocking him.