Does my husband have to pay me as part of our agreement in separation?

My husband decided he wants to separate and as part of that he signed a written agreement stating me would pay me so much money every month until the end of the year. He was supposed to make his first payment today and did not show up to do so. The payment was for rent on our apartment and now I am being evicted. Part of the agreement was that he got to use my car for work purposes because he works in Michigan and we live in Pennsylvania. But he has not fulfilled his end of the agreement. I want my car back. The title registration and insurance are all in my name.