OandU Your mother is acting like she is because she knows she can and that you will always respond and she can feel powerful and feel she still has agency.
In a way you are the origin of your own dilemma. I am willing to bet that your mother has always been emotionally manipulative and selfish, in which case it is foolish to expect her to change. She is what she is, and you just have to accept it and not expect her to care whether you need to work or make sure you have a reasonable pension. She never has and never will.
You need to accept her for what she is and either continue to be at her beck and call, despite it ruining your life, or tell her firmly as grandetante recommends that she is what she is and as that is the case, you will no longer co-operate. She is the cause of her own dilemma and must be left to sort it out.
You are doing what so many people do in similar and dissimilar situations, keep believing that one day a life-long selfish and self-centred person, will suddenly see the light and be grateful for all your efforts. It is an illusion. limited to works of fiction, where such a person, suddenly sees the light, and thanks their domestic drudge for all their efforts. Your mother will be selfish to the end, and never be grateful for your devotion, so stop looking for the approbabtion she will never give and act like she does and put your own life first.