Is there ever warning signs they would be safer in a memory care facility than living with you?

My Mom has been living with me and my husband for about 5 years now. She has dementia and it is getting worse as they always do. My main concern with her is that she has lymphedema in one leg and I care for it constantly. She still gets cellulitis every now and again and it is something that cannot be helped. It is a vicious circle with this condition. It is also very life threatening. If she does not tell me right away, it can go from 1 to 10 in an extremely short amount of time. There have been several instances since she has been living with me that she won't tell me until it is at a 10 and I have to call 911, or if she is able, get her into the car and get her to the ER right away. Then I get to argue with the doctors on what is wrong with her. Loads of fun. She spends anywhere from 2 to 3 days in the hospital getting loaded up with antibiotics and then she gets sent home again. The other thing is she has extemely low blood pressure and doesn't like to drink much fluid even though I have expressed the critical importance of this and have her adding electrolytes to all liquids. She has passed out from dehydration and no oxygen is getting to her head. Again, this can happen in seconds! I have already cut my work down to part time so I can keep an eye on her but she is getting worse memory wise. She doesn't remember that it wasn't more than a month ago we were at the hospital again for cellulitis. She wasn't feeling well that evening but instead of letting me know, I found her incoherent in her bed the next morning. By the time I got her to the ER, she was vomiting on herself and passed out waiting to be admitted! She recalls none of this. Sometimes I wonder what to do. Do I quit my job entirely and watch her, do I admit her to a memory care facility? She can still do a lot of things herself like getting dressed, showering, preparing simple meals, cleaning her place but she will not call me when she needs me even though she is steps away from me. This puts enormous stress on me because all I can think about is finding her dead one morning. Her common sense is gone. She has an emergency button that would bring the paramedics in 2 minutes but she forgets what that is even for. I find myself wondering what would be the smartest way to handle this without her going broke being in a facility or hiring somone else to watch her when I can't. Any of you who know me know my brothers are useless and will not help out so it's just me. She was an RN that worked in skilled nursing facilities her whole life which is why I am doing my damnedest not to send her to "deaths waiting room" but this is starting to become a real quandry on what is best for her under the present circumstances. It's eating me up inside. She refuses to go to any adult day care saying she is shy and would feel terribly uncomfortable and have nothing to say because she is so self conscious about her memory. It's a catch 22. Anyone else gone through this?