My brother passed away without a will. My other brother wants to sell. I want to keep it. I made a bank payment.

Ask a probate lawyer who practices in the county in which your brother lived and died to help you file an Application for Determination of Heirship and Issuance of Letters of Administration (or its Florida equivalent).  Once the court appoints you administrator of the estate, the bank cannot foreclose for six months.  During that period, you can find out whether the bank will allow you and your surviving sibling to take over the home or whether you must sell it to pay off the mortgage loan.  Please note that the bank loan the funds based on the credit, etc. of your deceased brother and on it being owner-occupied.  You and your surviving sibling may or may not have sufficient credit, etc. for a home which is not owner-occupied.