I’m sorry to hear about this setback. I’m crossing my fingers for you for finding a solution to your health troubles.
She’s also quite hard of hearing despite having hearing aids,
One thing to help you out with her on this. My aging mother was having the same problem and in talking to her I learned how isolating this becomes. There’s only so many times a person can ask someone to repeat themselves before its socially awkward. Many times the hard-of-hearing person eventually just gives up and nods pretending to hear and just becomes not part of the conversation. They can be a room full of people and be totally alone.
I found that her hearing aid brand has an external (bluetooth) microphone option and got her one. These are called “Buddy mic”, “Handy mic”, or “Partner mic”. It is a small rechargeable batteried mic that can lay flat in the middle of table of people (omnidirectional mode) or clipped on a lapel (unidirectional) that will isolate just the one person its next to (to combat loud noisy places and bring out the voice of the person being talked to). There’s usually a smartphone app the user can control modes and further filter sound. The one I got also has a 3.5mm audio input so you can plug it direction into a sound source like a TV which will pipe the sound right into the user’s hearing aids.
Find out her hearing aid brand and model and do a google search to see if hers has one. It will likely be a couple hundred dollars but it is a GAME CHANGER. My mother has had it and used it for months now and uses it all the time. If she is having trouble hearing in a conversation, she’ll quietly pull it out, set it in the middle of the table and is back in the conversation being able to hear everything and respond. She loves it!
The same may help your mother, and its possible some of the friction you’re experiencing from her may be her frustration with being sidelined because she can’t hear and her getting frustrated with that and it coming out on you.