How do I respond to my mom's negative responses when I have to correct her for certain things?

Likely, there is some reason that mom is giving incorrect information and it's likely not done on purpose. I'd make it a goal to not correct. You can go behind her and fix things, that might have been an issue like the wrong doctor appt. date. But, most things don't matter, because, if she can't recall, she can't recall and no amount of correcting will help. I stopped doing it. I'd also make comments about myself, like, I have to write things down, because my memory is just not as good as you used to be. I'd self deprecate, so she didn't feel bad.

I bet one thing she still knows is that she is your mother and doesn't want you talking back to her or bossing her around. It made my InLaws not want to be around one of their daughters as she was constantly telling them they were wrong. It made for unpleasant family get togethers. Daughter acted like they were lying and usually it was over something very trivial.

Has your mother been diagnosed with dementia? After a stroke it is possible that she has developed vascular dementia. If she has dementia, correcting her will not be useful and will aggravate her, and trying to keep her on track will aggravate you. Teepa Snow has some very good videos about how to respond to a parent with a dementia. The goal becomes to keep every one as content as possible which involves using some creative answers at times, (therapeutic fibbing) or distracting the person to another line of thought.

Does your mom have dementia? It's not all that useful to correct someone with dementia

Does your mother have dementia? Or perhaps mild cognitive impairment? That can make big difference, and reading about her condition will be helpful to you.

In any case, when is it really necessary to correct her? Don't do it unless it will make a difference.

If she is telling you about her day and she says Peter helped her bring her groceries in and you know perfectly well that it was Ralph, so what? If it is just the names she is getting wrong it is seldom necessary to correct her. If we corrected my mother every time she got a name wrong we could never have a decent conversation with her! (And this was before her dementia.) You can almost always figure it out by context. You don't "have" to correct her.

If she asks you to pick her up to attend a wedding next Saturday, verify that it really is next Saturday with a reliable source (someone else who will be going) or casually look at the invitation. She will have to know, of course, the correct date. But you really don't "have" to correct her on the spot. Sometime later in the week you can bring the correct date up in conversation, but don't tell her she is wrong.

If she is wrong, and has to have the correct information, think of it as informing her, not correcting her. And if feasible put it off a while -- she may have forgotten what she told you and won't realize she was wrong.

Nobody likes to constantly be corrected, and it is especially hard if you are beginning to doubt your own competence. Give Mom a break. Ignore the mistakes if they aren't important. Give her the correct information if she really needs to have it, but in such a way that doesn't come across as "You're Wrong."