Fraudulently my uncle made me sign the loan deed and made me a co-borrower

I got call from a loan agent. He firstly asked me relationship with my uncle. And after I told him that he's my Mama(mother's brother), he told me that he's making me a witness for a FD of 3 lakh that my uncle has took. I believed him and my mama was on call with that agent.

He made me sign the document digitally. When I looked closely to the document, I found that I'm a co-owner. Loan amount is 3lakh..but the payment with interested with be around 5lakh..

Now what should I do next..Pls help me out.