How to get paid for taking care of my grandmother?

If you weren't available, what would Gramma do? For example, would she hire someone else? Take cabs? Apply for Medicaid. Try to think of what would be done if you were out of the picture, and that may give you some clues about what can be done.

Talk to your grandmother, tell her you don't mind helping her now and then, but this has become a job for you and it takes time away from you from looking/having a job. She has a choice of hiring help or she can hire you with specified agreed upon pay. Tell her you prefer a job of helping her, but it's her decision. And it is.