I went through something similar, only I didn't cheat and I was on the receiving end of my ex's drunken rage after we broke up because he wanted to reconcile and I told him I had already hooked up with someone else. What he did was a federal offense and its a shame that I had to choose between pressing charges and trying to rebuild my life. Sure, he was hurting, but he felt his rage entitled him to putting my life and security at risk. I could have literally cheated on him and still this wouldn't have been justifiable. You were hurting, so you got drunk enough to feel comfortable with acting out the rage you felt entitled to unleashing on her.

Cheaters are scum, I get it. But that doesn't justify the way you terrorized this woman and everyone around her. You say that you were dangerously drunk when you did this - so who's to say that you wouldn't have escalated and physically hurt her? I've been cheated on before too (by my ex husband, no less), and there are plenty of other people with unfaithful partners who DON'T resort to traumatizing or terrorizing them.

I see a lot of people in the comments talking about whether or not you're a "good person," which I think is beside the point. Was this thing you did terrible and threatening and dangerous? Yes. Does it define your personhood for the rest of your life? No. Does that mean that you won't be a "bad person" to your ex? No, I'm pretty confident in saying that in her eyes you will probably be and remain for all time the person who made her and her family fear for her life to the extent they had to get law enforcement involved. But just because you're irredeemable in someone's eyes doesn't mean you can't be redeemed; it just means that they're not gonna be the ones to redeem you.

Having said all that, I hope your thanksgiving was a step forwards in terms of repairing your relationship with your dad.