<human>: Can you condense the text into a few key points?

He's getting more unpleasant towards my mom and me. Before the last few years, he was always the laid-back and forgiving one. Never raised his voice unless I fucked up big time.

But now he's short-tempered, coarse, and as my mom puts it, "needy". He's easily offended and rants about work (normal, but now he gets pissed and stays that way). He takes everything personally and curses more. We can't go long without him suddenly snarling/shouting at my mom in response to an opinion or request. That upsets me most. He storms out and calls her a bitch/etc. under his breath all the time. I did tell her she should stop getting on his nerves, since she tends to do that, but now I noticed he gets mad for no reason. 

When he's angry, I play stupid/diffuse things, but he doesn't take the bait like before. He's more opinionated on politics and thinks the world is out to get him. Lastly, he seems helpless. He's had a bad leg for months, but when my mom tells him to go to the doctor/ER, he'll say well she obviously doesn't care about his problems.

Sometimes it's fine and sometimes I want to bang my head on a wall. Don't know if it's real or just anxiety (life was basically fine til now, and this feels like whining). It's not like he's done horrible stuff, but it's been going for years, and since my brother lives far away I can't ask him for help. I just don't like being resentful of my dad, or avoiding him during the day.
<bot>: Former Most Easy-Going Dad Ever now acts aggressive/persecuted and it's making home an uncomfortable place to be sometimes. wat do?