How to get back property via release deed

My Elder sister and me had a joint Property of G+2 House. When I was mentally depressed bcoz of Seperation of my husband on the grounds my Mother-in-law separating him until I close my Housing Loan of 29L , my elder sister came forward stating to execute a Release Deed of 1 house for closure of Bank Loan from her end. But she took over my entire Land Share stating that she would execute a gift deed once the bank gets closed. During depressed situation for the sake of my husband I had signed the paper on Trust and got cheated. Bank Loan closure terms were very clearly mentioned in Release Deed. However Original Papers are at Bank Custody and Bank insisted that it would be handed over only to me on payment of Loan from my account. They rejected for my sister's 3rd Party Emi payments. My sister is paying me the agreed amount with rectification of release deed nor she is cancelling the release deed. She has cheated me. Pls guide me what step should I take to get back my property.