What to expect after radiation & chemo when you're the main caretaker

My dad has 3 radiation treatments left (including this afternoon). He's tolerated it extremely well, and his doctors keep saying they're surprised by how well he's doing. He's still having side effects, but not what they were expecting for an almost 78-year-old man with an inoperable grade 4 GBM.

They said at his appointment Wednesday that during the month between his last treatment and his MRI that we don't need to do anything. No appointments, no chemo pills, etc. Going to the hospital for radiation & appointments the past 6 weeks has been... a lot. I've missed a significant amount of work, because I'm the only one taking care of him when his siblings aren't able to come help. (They all live out of state, so it's a big commitment for them to fly/drive in to help.) My manager has been incredibly supportive since she was the only person taking care of her brother when he had brain cancer.

I keep telling myself that it'll get easier once radiation is done. That I'll be able to go back to work full time & not take money from my savings to cover bills anymore. But I don't know if I'm delusional thinking that.

What happens after this month-long break? I know he has his MRI and he's getting his Optune. I know he'll be on maintenance chemo. But how often do patients normally have appointments? Once a week? As needed?

It ends up being about a 5.5-6 hour round trip to get him to the hospital. I don't have a problem with it because it means I can take him to one of the best hospitals in the country, and I get to spend more time with my dad. But I'd be lying if I said I wasn't starting to get burnt out after doing that 5 days a week for 6 weeks.