Feeling anger

I’m looking for advice on how to feel anger and process it without acting on it. My mom is in a rehab facility and refusing to eat or do other things to help herself recover. I realize my anger is coming from my thought – “She should eat and try to get better.” “She should want to get better.” “She shouldn’t be upsetting the whole family.” Etc. I realize I’m thinking she should behave differently than she is. And I see that I believe that thought very strongly so I’m feeling a lot of anger, which then produces a lot of very nasty mean thoughts that I’d like to scream at her.

So far I’ve controlled the anger and not had any outbursts but it’s all been through suppression of the anger. I can also see that the suppression is putting a lot of physical stress on my body.

I don’t think I’m at a point of getting to neutral or even finding better thoughts or feelings until I know how to process the anger. I also think there’s fear (not knowing what will happen) and grief (she’s going to die) underlying this but right now the anger is closest to the surface. Any advice on how to start with the anger would be greatly appreciated. Thank you.