What's to be done when she dismisses every caregiver in the house?

Move the one that keeps firing them out!

Great big warm hug! You are such a trooper and you need to do what works for you and forget about pleasing her. She lives to be miserable.

Tell her primary that he can take her for a month and then explain how to do it better.

keepingup, If she develops diabetes from her weight, it just adds to caregiving complexity/headaches and reduces her quality of life, opening up the door to many other debilitating health issues. Remember that the caregiving arrangement needs to work for both parties or it doesn't work at all and another solution must be found.

Your profile says she has dementia. People who have dementia are not able to continue making decisions. If she's not able to look out for her own needs and welfare, I'd assume the duties. Are you the Durable POA? If so, I'd assume the duties and that means, she not in charge. If you have questions, I'd consult with an attorney who can explain what you need to do, if you need to file it, how to proceed, etc. If you don't have DPOA, I'd consult with the attorney about that too.
Sadly, people with dementia often are not agreeable. They may dislike a lot of things that are for their own good. They can be agitated, unhappy and resistent to care. Sometimes, medication helps.

The weight issue is tough. Her doctor likely blames you, because you buy the food and prepare it. Some people with dementia lose weight, while others gain. It's a difficult thing to address with everything else you have going on.

I am with Geaton here. Your house your rules. Think of it as the Caregivers are for you not her. Its not what wants, its what you want. I surprised myself when I started Caregiving. I was the oldest child and as such was given more responsibility and the one who lived in the same town. I was never taken advantage of but the only child here.

When Mom stopped driving I set boundries. One day a week for shopping and errands. We went out to dinner once a week. Appts made at my convenience, I still worked. She eventually lived with me. I was lucky, the woman I hired to bathe her was someone she knew. My Mom was easy to care for but it was the unpredictability of her Dementia and the incontinence I could not handle. I am a planner and like order. Can't happen with someone who has Dementia. I also overwhelm easily.

You will not be able to reason with Mom. If you need someone to clean, hire them. If you need someone to watch Mom, bath her whatever do it. I am not beyond threats. Tell her if she won't allow an aide, then you will need to consider placing her in an AL. Depending on where she is in her Dementia journey, she will understand or not.

Someone, on the forum suggested that aides be introduced as friends. Maybe just visiting the first couple of times. Or "helping" you and little by little u can back off.

If her behavior is really getting you down, then placing her may be what you need to do.

Your profile says she has dementia. If you are her medical (or even financial) PoA and you are the one hiring the caregivers, you instruct them not to take instruction from her. Hire people for household tasks that require as little contact as possible with her. The weight thing is an issue because if she needs to eventually be helped in/out of bed, car, toilet, she will need 2 aids and that increases the cost of in-home care and has some impact if she eventually goes into LTC (you have to wait for the staff to be available to assist). She is no longer in charge of what's going on...her DPoA is...if she indeed has dementia.

You can start touring Memory Care Assisted Living homes for your mother and get your ducks lined up for her placement outside of your home. You are not a slave, nor should you be treated as a second class citizen by anyone, even a mother with dementia.

Things don't get better with dementia, either, they only get worse. The anger grows and the abuse is likely to get even uglier. In Memory Care, she'll be with others her own age to hang around with, and she'll be cared for by a team of people who work 24/7 to do so. My own mother lives in Memory Care and gets excellent care there, I'm happy to say. When she runs out of money to private pay in 2021, I will apply for Medicaid to fund her stay in Skilled Nursing, if she's still alive (she's 93.5) There is no way I'd be willing or able to care for her in my home because she has way too many issues for me to handle, plus she's got a very negative and nasty disposition. I would never subject myself or my husband to such a thing.

Wishing you the best of luck finding alternative living arrangements for your mother.