Ok, first follow the following steps:
1) Breathe in.
2) Breathe out.
3) go back to 1
You've said "I know I did the right thing" a few times... is it because you're trying to convince us, or yourself?
Anyways, here's my two cents:
1) It's ok to be single
2) You can be aware, so you don't get sucked back into the relationship
3) You should be to be truthful to him about your real reasons for breaking up - for your own sanity. Be firm if he debates the reasons and makes it look like it's ok and expected for you to try and get back together.
4) Chill. Face your fear. Find someone or something (not self-destructive) to lean on while you get through this.
best of luck