Sears Credit Card

Here is my question,,,,my husband has a Sears Credit card. It is behind in the payments. My husband is now in a nursing home full time and all of his money goes to the nursing home. I know I need to pay the bill and the collection agency is wanting me to set up a payment paln on it, but money is very tight and I am not able to make the kind of payments they want. Please tell me what to do.