I get so frustrated with Mom. I feel like the worst daughter ever because I fuss at her. Anyone else go through this?

“Her husband is in the nursing home, so she lives with us”.

”Her husband is in the nursing home, so I need to consider residential care for her too”. (I fixed it for you).

Here's where you start. If your mother is able to get right up and go to the table for meals, then she's able to get up and use the toilet when she has to go.
Today is when you tell her plainly. If she is incontinent and going in her pants because she can't get up to use the toilet, you will not continue living in such a situation and will not help her anymore. Either she gets her act together or she can join her husband in the nursing home. Then do it if you have to.
I know this sounds harsh, but sometimes a good measure of tough love is exactly what a person needs. She also needs some socialization. What's available in your area? Is there a senior center? An adult day care center? If there is then she starts going two days a week as a condition for the two of you to stay together.
If you don't have these things, then get her a paid companion and insist that the companion take her out of the house twice a week. To a movie, out for lunch, to do some shopping. Anywhere but she has to leave the house. Force this on her. If you have to be mean and harsh about it, then do it because it's for her own good.
Believe me, you will see a big change in her when she gets past the refusal of your demands and will actually enjoy getting out and doing things.
You stop tolerating her abusive neediness and start playing that nursing home threat card every single day. If she wants to be stubborn and fight you on it, send her to respite care in a nursing home for a few days and that should do it.
Your story really resonates with me because my own mother is like yours. She has some health issues but is still capable. She is abusive and always has been and really hates me now. I remind her that I worked in elder care for 25 years so I know every trick, game, and behavior. I also know that no one ever benefits from being babied by another person be it their family or their caregiver.
Stop babying her right now. She gets up and uses the bathroom, or you stop being her caregiver.

I don't think Burnt realized that Mom is suffering from Dementia or I would be right there with her in her suggestions.

One reason I could not care for my Mom was because her Dementia was so unpredictable. I need order. I was also 65 at the time. Eventually I was able to place her in an AL where she adapted well.

There is something called "Showtiming" when it comes with Dementia. They seem "normal" for like a doctor but they crash later. This is probably what happened to ur mother with the wedding.

Even in the early stages those suffering from Dementia have short-term memory loss, cannot be reasoned with, show no empathy and it takes longer to process what is being said.

If your Mom is not in pull ups she needs to be. You may want to take her to the bathroom every 2 hrs. Don't ask if she needs to go, just take her. If she says she needs to go you help her up and take her.

Dementia causes depression. In the early stage those suffering from it know something is wrong. Your Mom has been thru changes. Her husband is now in a NH and she is no longer in her own home. Those suffering from Dementia do not do well with change. It may even cause further decline. Some people on the forum call it a broken brain, I call it a dying brain. As it effects each part of the brain, that part eventually dies. IMO they become like small children.

Dementia is unpredictable. There are good days, there are bad. One day she can make that sandwich with no problem, the next she does know what a knife is. As time goes on you will need to do more and more for her. There will come a time when you can't leave her in the bathroom alone. You will be cleaning her up.

Its really hard to except that there are things Mom can't do anymore, that you can't get her to understand that you are trying to do what is best for her. Her brain just does not process correctly anymore. Its all over the place. If she is happy sitting in front of the TV, let her. If you can get her out of the house, take a walk around the block. If you can't deal with this, then place her in a nice AL or in the NH with her husband.

She's sick. She has dementia and will never be the mom you knew before she was afflicted with this horrible disease. She can't think for herself. She is exhibiting wandering behavior by going outside at midnight and just sitting there. Next time she may not be just sitting there. She may walk into a dangerous situation and die from dehydration, hypothermia, or injury, and no one will find her for hours or days. Keeping her active? You can only do so much, and at her stage of the disease, it may not be that important anyway. So where do you go from here? Memory care, where they can restrict her wandering, provide suitable activities, and professionals to deal with her toileting. Please get her there ASAP for her sake and yours.

I so completely understand what you are going through. There is a period of time where it is so hard to believe that they can’t manage their behavior better, because we keep thinking about the person they were. Sadly, that person is gone and we are the ones who need to adjust. I am still struggling with this, as my situation is more recent - three weeks ago my mother was shopping, gardening, and paying her own bills. Now she does not know how to go to bed without my help. I am seeking help, because I can’t live this way. You have gone above and beyond, and now it’s time you get help, as much for herself as for her.

Your profile says your mom has dementia. If that’s the case she’s no longer capable of doing better. She’s not doing things to annoy you, her brain is broken and declining further all the time, that’s the sad reality of dementia. The question then becomes, how long can you keep up being a sole caregiver around the clock? It’s a huge job as you’re seeing. Sounds like it’s time for a better and updated medical evaluation for mom and a new plan for you both for her care

"I have been with her 24/7 for 6 months now. We go through waves of doing better than going in reverse. I just want to scream. She is 76. "

She can live for many more years. Are you going to continue being her fulltime caregiver?

You found her outside at midnight? So how can you get a good night's sleep? Sleep is very important. Sleep deprivation is a form of torture.

She needs to be in Memory Care. Do you have POA/HCPOA?

I would find care for her. You can’t do it all yourself and still have your own life too. I would let her know your dad needs a room mate. It’s time!

It will only get worse. Your mom from the past is not going to return. So you need to face facts and make a decision about her future and yours. This is the hardest part of this disease.

My friend had a problem with her mom and depression. So my friend made a rule - you must get up you must get dressed and we must leave the house everyday for at least an hour. It didn't matter where they went or what they needed to do. Get away from those four walls. Drive to the park and walk, or sit. Go to the mall, look at the things that "oooh that would look nice in Aunties house". Go to the next town and have lunch.
Is there a senior citizen group close by? Is there a library close by that needs a reader for children story time? Does the nursing home, where her husband is, have an activity time where she can join for the hour?
Prayers for you and yours