My mom has been a miserable, nasty, and hateful person all her life. As a mother she has dominated every aspect of her children's life.

I hear you loud & clear!!!! It sounds like we have the same mother! (you would NEVER call her "Mom"!
Let me tell you a couple of things that would have helped us a
LONG time ago. . . first, I am now convinced that she (our mother) has been mentally ill all her life! We can't go back and change anything, but it helps us not be angry & bitter! Just incredibly sad that someone couldn't help her long ago! Such a wasted miserable life--well, lives!(all those around her suffered!) In getting her to move in with us (the original plan was assisted living, but she changed her mind), I told her Dr.s I know they're giving her something everytime she's hospitalized or they wouldn't be able to deal with her either! Finally, someone confessed, they had previously denied giving her anything but her heart & bp meds. Turns out, it's an antianxiety/antipsychotic type med. WHAT A WORLD of difference !!!! So sad she didn't have these all her life. She could have had friends! We all now live together in relative peace-just battling the dementia! God Bless! I pray you can work something out & get to know there's not such a horrible person living in that women you call your mother!

She has had her way enough. Life changes and if she cannot change to get along they will drug her into submission. If she is as hateful as you say then you should feel guilty for ruining your families holiday with her there... instead of feeling guilty about your mother.
IF she KNOWS she is at the mercy of the aids and nurses she will either treat them better or face the consequences.

You are 60, you are done with her so just STOP. Visit her once a week, if she gets obnoxious tell her you are leaving and why and when you will visit again.

She was an adult when she treated you the way she did and you already have done much more than she deserves.

that being said I have spent the last 3 years of my life helping, advocating, running after my dad trying to keep him from being drugged into oblivion by the nursing home and it is ruining my life. I want to stop but can't. My dad was never mean to me but he left us kids to chase other women, yet now here I am stuck with him. It really, really sucks.

I'm going through something very similiar to you, I'm 52, an only child, with children of my own, my heart goes out to you. It's time to set your own "new" traditions.
If you feel you must have her over for a holiday meal then do it a few days before or after. Tell her that from now on you want to celebrate the holidays, quietly, so you can enjoy them.
Or simply tell her that you are going away this year.
If your mom is so controling, at some point she stood up to her elder relatives and said,"I want to do things my way," and you must do the same to keep your sanity.
If you can not go to see her often, call her(it's easier to end the conversation) and send her cards, pictures of the kids, or gifts to let her know she is in your thoughts.

I too feel that this story is similar. My mother was an alcoholic most of my childhood and up until abotu 15 years ago. Recently, she was diagnosed with dimentia and she has always suffered from Depression and Anxiety. Right now she is refusing to eat or drink unless I sit at the ALF with her... then miraculously everything is fine and she can eat and drink. I have started to leave her alone and only give her attention when she is trying to live... but she says she wants to die. My gut tells me that this is attention-getting behaviour, but she is only 90#... so indeed she could die if she refuses food and water for too much longer. At what point has she out-lived the "assisted living facility?"

My Father had bi-polar disorder and when he was in a manic phase he was very difficult to live with. It was suggested by my Father's Psychiatrist that when Dad became belligerent to leave the room, not to engage him at all in the behavior but just walk out. Same for phone calls, if he started on the tirade just say “have to go now / someone’s at the door-bye” and hang up. It is harder if the person lives in the same house; however the same rules apply, leave the room or go for a walk, do not engage or argue as there is no point in argueing with them. You can only control your reaction to their behavior, and if the behavior is not reinforced by getting the desired reaction it MIGHT change.

I have been combing the web for answers to a similar challenge, and I am comforted to read this thread and know that I am not alone. I am taking care of my very miserable 82 year old father who is ungrateful, crabby, vengeful and rageful. I would have thought I was doing something wrong if I hadn't witnessed his same behavior for the last 40 years of my life, with my mother, his sister, and every single other caregiver and family member that has ever tried to take care of him. Everyone has left him and now I am the only one left that has an ounce of concern for him but sometimes that even disappears as well. You also described my father to a tee when describing your mother. The guilt is killing me too, but so is putting up with his behavior. I wish I knew of a solution. I feel stuck.

Lilli put it in a way you can live with. What is there to feel guilty about? Is that feeling just a "habit" of being her daughter, that is just another way she controls you sweetie, with guilt.
My dad was like that. You described him to a tee. When I would go to visit and he would get stupid, I would just walk out. No sense in arguing or trying to make it all better.
I was not responsible for his misery and therefore could not fix it. You didn't make your mom this way, it is all about HER life choices. I am so sorry that she hurts you , but maybe you need to not keep voulunteering to be her victim. I finally realized with my dad, that out of some misplaced sense of obligation, I was voluntering to be hurt.
When I finally realized how crazy that was, I stopped.
Lilli said enjoy your own family and that is a great suggestion. Believe it or not I do not owe mean and ugly people anything, even if it is a parent.
You will be in my prayers and thoughts.. Keep coming back to this sight. You will get alot of support here. You are not alone

When parents get to this age they are needy, both emotionally and physically, so it is difficult to know where to draw boundaries. When there is diminished mental capacity, it becomes even more stressful. Our sense of humanity dictates that we care for someone in need. When you have a
challenging parent, those tasks take on extra weight.
I continually struggle to figure out how much of my life, my desires, and my energy should be given up to care for my parent. Right now, I am in danger of literally hitting the wall. My Mom has received wonderful care from my husband and me, so now she has come to expect it. I wonder if she had gone directly into an ALF if it would have been better in terms of her settling in and getting used to her new environment.
You are correct when you say, "the guilt is killing me." It will continue to gnaw on you until it manifests itself in an illness or mental breakdown.
You have made sure that your Mom is safe and well cared for. There is nothing wrong with limiting your time with her (it isn't quality time anyway). Try to divorce yourself as a relative and visit her to make sure that her basic needs are being met. Have a holiday at your home and perhaps take an hour to visit your Mom at the ALF and bring her a few gifts. She will probably continue to complain...but at least you will know that you did the right thing - because at the end of the day, and end of her life you will NEVER change her.
Celebrate with your kiddos and their kiddos. Honor grandma by making short visits to the ALF whenever you can, and be happy that you did not inherit her grim view on life...must be awful to live in her world.