Rental issue with ex-spouse as landlord

In my divorce my ex was granted ownership of our marital home; I was to be allowed to rent that home from him for $250 a month for a long as I chose to rent the home.

My ex has repeatedly refused to maintain the home (I spent $650 this year for a new water heater when the water heater quit).

My ex does not pay the annual county property taxes; I end up paying them to avoid foreclosure. He let the property taxes go for 5 years, and I paid over $4,000 to keep the house out of foreclosure. I pay the property taxes every year because he won’t pay them.

My ex’s grandson is in my guardian care and lives in this house with me. I am raising him alone.

My ex has in the past paid the homeowner’s insurance premiums; they are now delinquent. He has taken out a loan against this house in the amount of $75,000.

Since our separation agreement states that I be allowed to rent this house as long as I choose to rent it from my ex, is he required to maintain the home? to pay the property taxes? to pay homeowner’s insurance to keep the loan company from calling in the loan against the house?

Thank you for your answers to these questions.