Urgent suggestion on loan repayment failure

Hi, While starting my business I have taken a loan of approx 8.5 lacs from my cousin on interest in 2015. I was a beginner at that time so i was having no idea about market interest , so i committed interest rate whatever he has asked . Since 3 years he has taken approx 8.20 lacs with me in different credit card bills and account. My business is going in loss and I have other liabilities also like my education loan and family responsibilities . I have asked him for consideration and given the clause that almost I have given you the principal taken from you so better we go for settlement and tell me a consolidated amount so that i can close this matter in a fix period of time . But he is not ready to compromise and according to him the principal is 11 lac ( 8.5 Lacs + pending interest ) and he wants interest on this amount also. I told him I am unable to pay this and this is complete plundering , he has my signed cheques without date on it of 9 lacs approx. He is saying he will bounce the cheque and will take legal actions like residential property acquisition and will threat to my family. Please suggest, I am ready to go in legal way also