dear LM, if I can abbreviate your username, and want to thank you for trusting us here, and hopefully you get plenty of support here, so you have come to a good site.
I do know how devastating it is to see your mum deteriorate before you as the same happened with my Mum who was also in a nursing home.
You see them go from being an active, thoughtful and loving person to one which we truly hate to see decline so rapidly.
My Mum was the same as yours just look at you as if you weren't there, and even when you tried to kiss her she would put her hand up and block you from doing so, just as though you were a stranger, so you come away depressed, and this is what is happening to you unfortunately, especially as you were once so close.
The number of times she would ring you would probably be about nothing, or not make any sense, and this too would be very upsetting for you.
It's not that we want them to go it's just that we want them to finally find peace, and not to be tormented by they illness any more.
Your daughters are very astute and are worried not so much that you will end up like your mum, but fall into this pit of depression, but I think that you have, it's just that you covering it up, and that's why you need to begin to see your doctor and then a psychologist or perhaps a psychiatrist, personally I prefer the former, but others feel that a psychiatrist would be better, as they administer medication for you.
I know the strain that this is causing you, and you will always love your mum, but you have to prepare for when the day comes, but you can't do this unless you receive some help.
I would dearly love to hear back from you. L Geoff.