Need your feedback on how to keep my sanity!?

I've been the one to answer in the past, but now I need the communities help! I have been responsible for having to care for my mother for the last 20 years. I have put my life on hold, unable to pursue the career I would love, and having to forgo any type of social life or friends as well as accept menial jobs to accommodate her needs. Granted she is now 95 years old, but she is far from feeble. I moved her into my home to make sure she is taken care of and not alone. Everyday I make sure she has healthy and wholesome meals that are prepared sometimes ahead of time, so that when she eats, she is eating something other than frozen processed garbage, that I could easily, and cheaply make in the microwave. But what does she do? She raves about things I didn't make like donuts, pastry, ice cream, candy, that someone else provides because they just think she is so special and deprived because of her age! She manipulates everyone around her with her woes, which are minimal because she sees her doctor as often as she requests. I have no health insurance because I pay for hers! She has a totally depressing attitude about everything, yet everyone always asks about her! It's always poor me, and I am sick of it! I know at her age she won't last forever, and it may seem like I'm being selfish, but how many people her age are confined to convalescent homes where no one gives a damn about them would only wish to have the situation she whine about?