What should I do?

My son's 86 year old grandmother needs live in care because she's in Stage 2 Multiple Myeloma, has many other doctors appointment etc. She has no female family members and her church members who love her so much can't help or move in so I moved in with her. I'm from another city and I'm her Provider. I make $1000 a month for 4 hours a day 7 days of the week. I have the use of her car (on car insurance) After my paid 4 hours some days, I'm doing things for her. Am I required to pay rent, utilities food etc. She's on SS and gets a small check and if I should give her something what is a good price. I've been with her 2 months, came her with a $1000 and I'm broke minus $300 for paying taxes on my house b4 leaving. I got my lst work check two days ago.