No matter what I do, my mom will almost always find something wrong with it

Yes, certainly your mom's difficulty in having meaningful conversations with people results from the Alzheimer's disease process which weakens her brain function.

Feeling a sense of guilt in relation to a parent, is pretty common for everyone.

This is because as little kids and babies, we had a strong reliance on a parent and believing every word they sad and wishing to follow each action they ask or demand, was for the benefit of our own survival.

One way of coping with your feeling of guilt is to examine it.

Ask what it is you're feeling guilty about?

Chances are that your sense of guilt is less due to what you're currently saying or doing to help your mom.

Very likely, your guilt feeling is awakening the sense of obligation that you and all of us feel toward a parent simply because parents seem to have unquestionable power when we are very young.

After all, you're thoughtful enough to write a question, so chances are great that you're already actively involved in caring for your mom.