It sounds like the specific issue you are addressing is whether or not to apologize for blowing up at him.

I certainly can relate to feeling terrible at blowing up at someone. And to wanting to clear the air.

You are concerned that if you reestablish contact he might say harsh things to you. Another concern though is that he might try to reestablish contact with you. It sounds like you see him in his true light and know not to go back to him. But on the other hand he is tempting and you are lonely.

Thus, it is risky to apologize. Dangerous.

What are other methods you might use to handle negative feelings, regrets?

Maybe you could sit with them, just look at them and listen to them.

Maybe you could weaken them through something like exercise, community service.

Maybe you could heal yourself by studying anger management. Thich Nhat Hanh has a good book about it:

https://www.amazon.com/Anger-Cooling...r+thich&sr=8-1

These are just ideas, but my belief is that dealing with regret over blowing up by having a plan that does not involve contacting him will be healthier and safer than apologizing to him.