Loan taken against for marriage

Hello, One of my cousin had taken money for her daughter marriage in the year 2014 September ; Since I didn't have money to lend them, approached the known third person & from them i had taken loan amount about 7.5 lakhs & gave it to my cousin with some interest agreed. (3 lakhs online transfer & 4.5 cash). My cousin had given blank cheque of 7 lakh. Now it's been 5 yrs, my cousin is not ready to give the loan amount nor she is paying the interest; since i had given my surety, i'm paying the loan amount. She doesn't have any property on her name, she is separated from her husband but she has property from her in-laws side. Her daughter & son are not ready to pay the loan amount. Online transaction of 3 lakh is done on her son's account. Daughter's husband also has from well settled family. And her son's wife also from well settled family. But both son & daughter are not ready to return the amount. So now, can i file complaint against my cousin(blank cheque) & her son(with online transaction) Can i get back my money ? Will it have any problem in getting the money as cousin doesn't have any assets on her name? can she claim of her son's or daughter assets & give back my amount ?? If i file how long does it takes to process, i'm in a trauma as there is a pressure from my in-laws side? i had undergone many health related issues due to this ? Does this process takes months or years? should i need to be for every hearing(as i'm a mother of small baby) ? Kindly assist if there is any faster solution to get back my amount. Thanks