Parent getting meaner, no joy left

I am new to this forum and new to learning about Alzheimer's. My dad has had a steady memory decline but it finally was diagnosed as Alzheimer's. Recently I've noticed things have gotten way worse.

Nearly every time we visit, the tension builds and he has an angry outburst directed at my boyfriend. This time he took a swing at him. It was ugly. He called him every name in the book and threw us out of the house. For years my mom has been relying on my boyfriend to help around the house - fix toilets, clean gutters etc because my dad isn't capable anymore. I assume this is threatening. Plus anytime his routine is disturbed, the pressure builds (it happens when my sibling + his family visits too.)

This particular visit was long because my mom underwent a hip replacement. Since she's his caregiver, we had to take care of all her needs PLUS his (he's incontinent and bedding needs to be washed daily, plus administering meds, cooking, shopping, etc.) They both insisted he come to the hospital which was a disaster. He wandered off, had an angry outburst, told me to go home (3000 miles away). She had complications with anesthesia, so they kept her overnight and he thought she was going to die… he cried… I felt so bad. He was in such a downward spiral of negativity that night.

This time I notice changes like this: when she came home from the hospital the next day, he registered no emotion. He just stared at her and then went back to his book. She asked "aren't you happy I'm home?"

After our final night blowup, she said "you kicked them out of the house. You may never see your daughter again!" No emotion from him. He was never like this! He always had an abusive side, but also a teddy bear side and that seems to be gone. I don't even see him smile.

Advice on how to proceed? My mom needs the other hip done in a few months and needs our help, and I need my boyfriend's help too! He has a background in the medical field and made sure nothing was missed. I know she wants us to stay at the house, but I'm afraid to, and it's embarrassing that my dad acts this way! And unfortunately his explosive outbursts are a trigger for me b/c of how he bullied me as a child. Fighting fire with fire does not work in this case!

I want to support my mom especially during surgery. Should we get a hotel next time?!?! It's too much drama! We also are thinking of limiting contact with him and walking away when we see the signs of an episode coming on. He grits his teeth and makes fists. I also need to limit how much he sees in the hospital (she was SO pale and weak after surgery) and he's getting agitated at the suggestion of caregivers coming to the house to help with laundry/ helping my mom shower. But he cannot be depended on (he also has a bad knee and can barely walk). They just need to show up, I think. Advice please, sorry this is so long!!!