I also have a fractious relationship with my mother, and she is also very stubborn. She has always been bossy and very opinionated and has no concept of others having differing opinions. It’s not just me, she is the same with my siblings, she was the same with my Dad and even told her own Mother what she should/shouldn’t be doing or thinking. Undoubtedly it does wear you down over the years and because of my career choice and learning to become assertive, I was able to deal with her verbally, instead of just keeping quiet to avoid exploding ! I have been able to address many historic issues with her, when she has bought them up, so I have got rid of a lot of my angst. She does not like it when I have proved her wrong, has never admitted she was wrong and never ever apologised for anything. She has always done her best in her eyes and that’s all there is to it !
Have you tried writing a letter to her, writing down all your feelings ? It may never be sent, probably best that it isn’t ! However, it does help at times just to get it all out of your head. I visit Mum once a week, take her shopping and out to lunch, plus I ring her midweek, I can do no more. She is unsteady on her feet but refuses to sell up and go to warden assisted accommodation, but she does have Lifeline. Just accept that you can do no more, and be kind to yourself. The fact that you are agonising over this proves that you have a good heart .... so just learn how to let it all go, live your own life and be happy.