Is it worth it at all to honestly and calmly confront an elderly person who consistently hurts and disrespects you?

How about the objective of you yourself surviving in decent shape. This is not all about your mother it is about you too. You matter too.

Rosses, have you ever confronted her? Would it really be so very terrible if you did? Why does she have so much power? So what if she sulks and skips a meal -- most people are going to survive that just fine and unless she is truly very mentally ill I'm sure she would want to eat eventually. She certainly doesn't have the right to mistreat anyone, and unless she is now demented or mentally ill and doesn't realize what she's doing, I'm not sure why you are tippy-toeing around her like she's a bomb that might go off. I guess I would respectfully suggest to you that the world wouldn't end if you insist on basic courtesy and respect, the same that I am sure you offer her. I'm so sorry this is happening.

I'm not quite clear what you:

expect
hope for
would hope for if you were describing your ideal "fantasy" mother, so to speak.

Calmly, respectfully and (in the best sense) assertively confront her and challenge her unreasonable and unkind attitudes and behaviours, hmmm. What would you hope would be the outcome of doing that? - is the point I'm getting at.

Your description of your situation, and your account that you have turned your life upside down to devote these years to providing your mother with the best possible care, I find quite heart-breaking. You are the little baby monkey clinging to that cold, hard mother-monkey wire effigy.

Do you have any access to therapy, counselling or at least emotional support in dealing with this relationship?

There is also another perspective from which to view your shared situation. Try this exercise in assessing her needs objectively:

From your post, it seems she needs assistance with

eating, which she won't take from you;
pain relief and physical wellbeing, which she won't accept from you;
mobility, and she resists your encouragement.

Is it possible that her well-developed determination to oppose and deride you is actually counterproductive when it comes to her welfare? It doesn't matter that this is her doing, her "fault" if you like. The fact remains that because of it, she prevents you from being the best person to provide her care.

So unless you think the stimulation she receives from having you around as a handy scapegoat is beneficial to her - and I'm not being rude or sarcastic, that is a genuine possibility even though it then creates serious issues around your wellbeing - if I'm honest I question whether the current arrangement is right for either of you.

Mm. It's this bit, too:

"Unfortunately my mom’s ways and attitude towards life -and me- has always been the same, now worsened by age."

If pain or frailty or illness made her crabby and difficult, then it would be reasonable and compassionate to overlook it until the moment passes, and do what you have been doing, and let her behaviour wash over you.

But that's not the case, is it? Her battering you, emotionally anyway, and you sucking it up and *believing that this is the natural order of things* is just not a reasonable modus vivendi.

And your reward is a bare - very bare, not to say skeletal - acknowledgement that her life is marginally less miserable than it was when she was living alone. Which, in any case, she only brings up when she's dwelling on past sufferings. And, don't tell me, I bet she works in a little nuance of accusation about whose fault it was that she was living in desperate loneliness, with no one there even to hand her a glass of water, and I bet she doesn't blame her own poor planning. Am I right?

Other people can provide human presence. Other people can fetch her a drink. And because, while they care about her welfare, they don't love her or long for her love and approval, those other people won't get beaten up.

You are not the only person who can provide excellent care for your mother.
Keeping quiet is not the only way.
This is not your only choice.

I "had it out" ONCE with my mother. I didn't feel better, I felt worse. She sat and spat venous things back at me, when all I wanted was to clear the air about some situations surrounding the abuse I suffered at the hands of my older brother.

Epic Fail.

I am in therapy, and probably will be forever. Mother is just mother, living her fantasy life and seems just fine with it.

What a waste of time and energy it was trying to get her to simply acknowledge that Yes, she knew these things were going on and Yes, she felt bad about it. She refused and then blamed ME for driving said brother away from the family (no, it was b/c he began to inappropriately touch the nieces and SIL's. That ended his connection with the family.

I would never bring this up with her again. No point.

If she gets snippy with me, I leave. Period. I don't give her power to hurt me anymore.

The first thing I would consider is whether your mom suffers from dementia or mental illness. Is she capable of understanding what you say to her? If so, I believe I would speak up. If not, probably not, or only to vent.

You've been the one that planned your life poorly? Huh? I never planned that my husband would have dementia, or that my mother would. Should I feel guilty about that? Well, if I should I'm doing it all wrong, because I feel not one shred of guilt.

You mother has/is making choices about her own life. They are HER choices. There is absolutely no cause for you to feel guilty about them, or to go along with them, or to incorporate them into your life.

If you'd planned ahead better, could you have avoided being an only child? Could you have prevented your mother's mental illness, or her cancer? Would your father have lived longer? Would better planning on your part have made your mother a less difficult person to deal with?

You seem to have amazing beliefs in your own powers. If you'd only done x or y or z you could have changed the outcome here. You simply don't have the powers you are giving yourself credit for. You, like all of us, are only human. Believing otherwise is, in my opinion, delusional. Feeling guilty for being only human seems a very unhealthy choice, to me. Feeling guilt is useful if it inspires you to change some behavior going forward. I don't think that your enormous guilt is going to change your situation at all.

I think you are choosing to be a martyr. Caregivers sometimes do that. As long as it is your conscious choice, then go ahead. But, do martyrs get to complain? I'm not sure about that point. Most of us regular humans do complain now and then, or even more often when things get tough.

I doubt there is a "light" in my post, or at least not one that you can accept as long as you believe in your own supposed superpowers.

My mom hasn’t been diagnosed with dementia, and although I know her mind is it as clear as when younger, I know she understands what she says and the implications.

But if I respond she will keep a version of what I said totally divorced with reality, victimizing herself and making me into the worst possible daughter with the consequences I mentioned above!

There is no really easy answer to this. If your mother is mentally ill or she has severe dementia, nothing is going to be gained by fairly or explaining anything that her words and actions are out of place or wrong. It will make you feel better, but it won't change or help the situation. Your mom's health is breaking down, and the rational part of her mind is shutting down. Though as caregivers, we know that, it doesn't make us not attempt to reach that part. Allow me to say this: it won't reach that rational part of her brain.

If it helps you to explain it to the mother she used to be, then explain it in writing (to get your own frustrations out because there will be a lot ) because it will maintain your dignity and keep the help she needs while her health is failing. Any temporary relief I've experienced in explaining myself reached my mom's rational mind for about 3 seconds, and disappeared in 10 minutes. She won't remember what you said.

So anything you to do with explanation will simply be for your benefit, so choose what you think is best. Since I'm on the computer, I can type out my rant and delete it on a word document. As far as making it less difficult for her, I believe you already have made it so; she just can't express it.

You say you recognize she is a Narcissist and always has been, so nothing you can say or do will ever change that. There is no reason for you to allow her to disrespect you and treat you like a doormat though, set some boundaries and decide on the consequences when she crosses them... there are many threads on the forum and web that address how to go about this better than I can.