Dealing with People Facing Addiction

My parents and I had to move out of our previous home this summer, and before that I left the house because I couldn't take any more of the BS from my father's family. Since I came back, however, I noticed that my father's drinking has gotten worse. He was always a drinker--he would have six beers before heading to work. It was rare to see him really drunk, but now he gets into these drunken rants and lashes out at me and my mom for stuff that happened twenty years ago on a weekly basis now. We can always tell when he's had a lot to drink when he wets himself, and this will go on for two or three days before he sobers up and starts the process all over again.

For me, it's hard for me to try and be supportive because a few days before I moved back in with my parents, I was couch surfing with a friend who also has a drinking problem and a heavy dependency on weed. They were volatile the entire time I was there and were also getting mad at other mutual friends for not giving them enough attention on their own problems. When I called them out on their behavior, they called me ungrateful and kicked me out of their house.

These two experiences have drained me emotionally and mentally, and it's making me resentful towards my father. Aside from therapy, I'm not entirely sure what steps to take in regards to living with someone whose addiction has got so bad.

TL;DR: Dealing with two alcoholics is taking its toll on me and I don't know how to go about caring for myself while living with someone whose addiction is getting worse.