Is it wrong to stop forcing my eldery mother to eat?

My mother who is 87 started off with Alzheimer’s that turned into dementia with sundowners. I’ve been taking care of her for almost 8 years now. As the years have passed, she has become incontinent, doesn’t recognize anyone, chokes when she eats or takes her pills, babbles when she tries to talk, no longer walks. When she stopped eating a few years ago, I would coerce her to eat every hour until she started eating again. But this time it’s different. She does not want to drink her sweet tea or her ensure, she only eats a few bites of watery flavored oatmeal. She just stares into space a lot. I've decided to just let her be. I currently crush up her pills in sugar water and use a baby syringe to give it to her, I still feed her, but when she turns her head away, I stop. She now only eats a few bites twice a day, in the morning and before she goes to bed. She takes a few sips of sweet tea and that’s all she wants.
She has always said that she never wanted to end up like my grandfather, but currently she is just like him. She saw her Dr. a couple of month ago , I was told her blood work came back perfect, but her mind was a different story. I’m always being told that I’m doing a very good job, but at 57 I’m tired.
I spoke to my siblings and they tell me that it’s time to quite forcing her and just let her be. If she doesn't' want to eat or drink, just let it be. As long as I try and it’s available, that is all that I can do. I feel guilty for the decision in not coercing her to eat or drink. Yesterday was the first time I didn’t make her eat. My mother was as mean as a snake and just as nasty, but she is still my mother and I’ve been taking care of her for a long time now. I keep thinking is the decision to not make her eat and drink because I’m tired and not thinking clearly. Am I making a bad decision? Is it wrong to let her go? My parents were married for 60 years. My father went suddenly and has been waiting for her for almost 8 years now.