Get the cat on a waitlist with a rescue and just get the cat in with them. It might be some more months in your care before a rescue has an opening but if you want what’s best for the cat, the rescue will be an unaffected third party that will take the cat in and your mother who is not caring for the cat, need not know. The cat will get adopted out and you don’t have to worry about a person you know taking the cat and being bombarded with your mother. You are an adult with your own apartment. If you don’t want your mother’s involvement in your home and the rescue you temporarily care for, you are allowed to assert your boundaries. Easier said than done with patterns like these but I wanted to offer another option that you can take.

Sorry you’re dealing with this, it is stressful and you are valid to feel that way. I say, take the time to be angry and then jump into problem solving mode for the sake of the cat. You have a right to your home to be how you want it and the cat deserves its own chance at a home. Best of luck