SS-
First of all...hugs to you. Second, i don't know why you are ashamed of your behavior...in my opinion, nothing to be ashamed about. You acted out your frustrations, in a very difficult situation...its a wonder more of us don't beat the crap out of them
Look, things happen...its life. I think it is better to get it out then keep it locked up inside. Sometimes, i think that is what my H and I need...a real screaming match...we never fought. I think, sometimes, we walk around on eggshells, so afraid to do or say something that will cause a setback. Well, that can be emotionally draining. Perhaps you need to take a step back and clear your head. Don't have contact with him for awhile..it will allow you both the time to cool down.

he said he's probably going to have to tell the OW to steer clear and that I've probably ruined any chance they had.

Okay, WTF? Is this supposed to make you feel bad? Honestly, the things they come up with to blame us for in order to alleviate their own guilt is almost comical. So, lets see, his W ruined any chance he might have had with his GF...well, too fu..ing bad! For the love of pete!

Listen, about a month ago, i did something that i thought was going to ruin everything with my H...it didn't...not any more than it was already anyway. Don't place so much signigicance on it...i am sure he isn't. Try to relax...find something to maybe take your mind off of it. And above all, don't beat yourself up over it...learn from it. Take care today.