A friend who asked me to care for him went into the hospital for open heart surgery and gave someone else POA?

Who has "regular" POA? Did your friend appoint someone to look after his financial affairs? Having medical POA has nothing to do with that.

The person who has financial POA (if anyone does) can use your friend's accounts to pay his bills.

If there is no one in charge, I guess if I were you I'd contact utility company and explain that the homeowner is in the hospital and there will be a delay in paying this month. If there are other bills coming due I'd do the same with them.

Let us hope that your friend makes a complete recovery and can home.

Do you have your caregiving-for-room-and-board arrangement in writing by any chance?

This sounds like a good time to look around for new shelter for yourself. I can't tell what is going on from what was written. Caring for someone for a shelter over your head is not a good situation if they require a lot of care. You have to be able to feed and house yourself when they are no longer there. I hope that you are able to find something quickly. You are not responsible for your friend's bills.