This kind of care can really wear you down - like Fresia said, if you were a bad daughter, you wouldn't be there for your mom as much as you have been.

But you need to make sure you have enough space for yourself, too. Sometimes it's tough to set limits, but it kinda sounds like you need a break, and that's something that your mother ought to respect. You need to meet your needs if you're going to help anyone else with theirs!