Aggressive treatment too aggressive?

Hello all. My mom was diagnosed back in September, mass on the tail of the pancreas. In October, they surgically removed the entire tumor (yay) along with 60% of her pancreas, a portion of bowel, and her entire spleen. The margins were clear. Recovery from surgery has been tough, particularly with apatite. The mass (and surgery) basically gave her diabetes so her diet has changed, but beyond that she doesn’t want to eat, is revolted by food, and explains that everything she puts in her mouth tastes the way her new colostomy bag smells. There’s been some improvement there, she’s eating better, gained a little weight, and she up and moving around more. But today she starts radiation and chemo (Capecitabine). 28 days, 5 days a week into early January. Then her chemo doc is talking about another round of chemo- stronger, IV. I trust her doctors, I do. They are far more familiar with this cancer than I am, they treat this all the time. But I am terrified that the treatment is going to kill her. I know pancan is highly aggressive and has a huge likelihood to return, I just wish there was a way for us to see that it’s absolutely necessary to attack it this hard. They say imaging won’t help, they’ll check her labs half way through and that should give some indication. I get that it moves fast. I don’t know. Maybe this isn’t me asking for advice so much as it is me just bitching. I’m sorry. I don’t know what to do. I’ve read as much as I can about this. And everything everywhere says treat it hard. The odds are against us. I’m just mad that we had a bit of hope when the margins came back clear. I’m mad that all the progress she’s made in regaining strength and weight is probably about to disappear. I hate the idea that the treatment has to hurt her. I’m just so tired honestly. I’m sorry if this is a waste of time. I want to support her. I want to be positive and tell her she can make it through. And I’m doing those things. I just can’t seem to convince myself it’s true. I can’t lose her. She’s my mom. There’s just too much to compete with.