@Hikaro: One of the worst things about it is that he was my nicest uncle. While we were in McCall we sat and talked about science for three hours. That was just yesterday. He has bad depression problems so we've been trying to help him out. He's been living with us, we always take him on vacation with us, and we've always had a good time with each other. He was just drinking too heavily, and it got the better of him. I will still never forgive him for hurting my parents right in front of my little brother. He also disowned my mother, who has been trying to help him turn his life around, but he's completely ungrateful and refuses to take any responsibility for his actions. My moms been crying all day, not because he attacked her and my dad, but because he made it clear he never wants to talk to her again. It cheered me up a little after things had settled down, and both my parents said they proud of me for taking a stand to protect them.
In my experience, depression or alcoholism alone (although they tend to go hand-in-hand) can easily take a good man down the road of destruction, and coupled with a heavy case of denial and refusal to even recognize that there's a problem in the first place are just the icing on the cake. During my time in the Navy (especially with the ships I was stationed on), I've seen this kind of thing happen too many times: A guy might be a ship-shape sailor when sober, but come a payday weekend after blowing a substantial part of his paycheck on booze, and he'll be starting a barroom brawl that spreads to three different establishments... (and since I got stuck on Shore Patrol duty often enough, it's entirely likely I would be one of the guys trying to break it up before too many people got hurt or too much property damage occurred).
Still, your parents are darn right to be proud of you: I'm a war veteran, who (due to my job being combat related) was also trained in physical security (a.k.a. armed guard), and even I would have been shaken up pretty bad by something like that. You also handled the situation about as well as anyone could, training or no, so Bravo Zulu
, I mean it.