I feel so defeated in my marriage.My husband'£ mother is 94 and stubborn and needs to be in a nursing home or assited living place. My husband is her only child..she rules him and he is so passive. She has limited mobility..extreme swollen legs and refuseto go to the
https://www.agingcare.com/articles/bad-behavior-by-elderly-parents-138673.htm
My MIL used to be like her. She always made circumstances to make me feel down. I can completely understand you. But just realize , it is an extremely difficult situation and you are not in anyway responsible for that. Things are going to get worser. Be brave and face it! Know that the age is playing tricks on her and she is weak inside. It need lot of courage to deal with this.
From your words, I assume that your DH is her pet. If then you can use him for getting out this difficult situation. But without his cooperation, nothing can work out. Make him realise the situation and ask him to support you to pull you out from this mental trauma.
Why don't you get a senior medical alarm for her? She could call you whenever there is an emergency.It is very useful...I live in Canada and guys from My Alarm Care installed it for our MIL . I am sure you will have something similar in your city you are living. We took it for a monthly rent and the guys from that company installed it for us!
Also, tell us whether your MIL lives with you.