How to deal with difficult mother???

Mom, 77, lives with me and hubby. Just had her second knee replacement 3 weeks ago. That went well and she is able to get around quite well. Probably a lot due to having her other knee replaced a year and a half ago.

BUT she is being very difficult and driving me NUTS. To me she is negative and complaining most of the time. Pain here there and everywhere. New pains in hand perhaps due to RA flareup perhaps from having to go off her RA meds to have her operation? Knee pain which I keep telling her, yes of course your knee hurts, you just had an operation. Back pain which is chronic and she does nothing about.

Taking max tylenol a day and 5mg oxy 3 or 4 times a day. Usually 3 because she forgets or doesn't think she needs it overnight. Okey dokey.

Lots of complaining about her stomach/digestion and I know a lot of that is due to the oxy. Encouraging more water/fiber with not much cooperation. Except the meals I give her have plenty of fiber.

Knee/leg very swollen so trying to get her to drink more water. Should be at least 8 a day but maybe does 4? On furosemide which isn't really helping much but last operation this took time also.

Home PT is coming 3 times a week. She cooperates pretty well with him but does next to nothing when he's gone. Whenever I try to get her to do it, I am 90% of the time met with negativity and excuses. Then I know she will lie to the therapist and pretend she did a decent amount of exercises when if she did 10% of what she was assigned, that'd be a miracle.

So basically she does as little as possible and expects her pain to get better and her situation to improve. Magical thinking.

So I called her doctor to try to get an appointment and she is having a phone visit today. Which she doesn't think she needs. Well, you're taking the pain meds they think will help and they're not doing the job sooooo???

For the last 4 days she has been just focused on the pain and crying and complaining. Had two conversations (arguments?) with her yesterday and she seemed to rally a little bit after that but will not engage in conversation about this. I have not wanted to talk about any of this because I know she will be impossible but I have given it 3 tries. Now I'm hiding in my room before I totally lose my mind. She just sat there, not looking at me, and I said (perhaps stupidly) what are you thinking to try to get her talking and her lovely answer was "you don't want to know what I'm thinking". Nice.

I feel like I'm dealing with a 2 year old temper tantrum and/or a freakin teenage girl. Everything I say she goes against. Very contrary to me, even before this operation. Typically she really is a nice person and pleasant. Even to me. But, lordy, I am at my wits end.

I can not do more for her and her recovery than she is willing to do. I am disgusted and angry and sad, etc. I resent the fact that I am, AGAIN, putting more energy into her recovery that she is. If she put half her negative energy into positive forward motion, she could be so much better.

Also tells me things like "I don't want to take more pills or go to more appointments" when I suggest fixing some of her other problems. It's just such a short sighted negative attitude. WHY?? I ask her why wouldn't you want to take one more pill or go to a few appointments to be rid of problem X? Maddening.