Any, yes I agree, no contact is the best way to go. When I mentioned about telling him you were cutting contact, I in no way meant you then needed to have a conversation with him (just want to be clear on my intent there).
I think it is polite to let it be known, but then that's it, it's not a conversation : ) - of course you will make your own decisions on that.
There is a book often recommended here - Codependent no more - by Melody Beattie. I'm not saying you are codependent, but the book has a lot of wise information and it speaks about boundaries.
Your guilt is misplaced I think, that happens a lot! He needs to take care of his own issues and feelings, that's not up to you. I hope you start taking care of yourself and looking out for yourself. It's great you are taking a few days to clear your head, I would suggest taking several weeks (or months)!
You didn't Cause it, can't Control it and can't Cure it (the 3 c's).