Contract of adhesion

Dear PAO,

My husband and I contracted a loan with a bank purposely to help finance our small merchandising store, which is on the verge of bankruptcy. As collateral, we mortgaged the land on which the store is located. In the succeeding years, we renewed our loan to increase the loan amount. However, the ready-made amended mortgage contract provides for a dragnet clause, which we later learned contains a provision stating that it secures payment of obligations already incurred or may be subsequently incurred. Due to dire financial constraints, I signed it. Is that valid?