This is my response to you:
1. Your father has created a lot of problems for you and left you in deep trouble;
2. You just don't need a good lawyer but also a very good chartered accountant;
3. A chartered accountant will help you asses the way to pay off all the loans and devise tricks to avoid the burden of the banks;
4. You will need to pay the loans anyhow, you can run away from from time to time it but you cannot keep hiding;
5. You must search for any fixed deposits your father may have kept;
6. Is there any property, land or plot or anything else which you can mortgage or settle with the bank?
7. Why don't you ask the bank to trouble your father if the loan was taken on his name, why should you suffer?
8. Your mother could have filed divorce and the burden would shift away from you and your mother and sister;
9. If you have not reaped benefits of the loans then why should you be paying?
10. The method of last resort is to sell the house and pay off the loans, but it is still better if you shift the burden on him;
111. If your father is unheard of for 7 years or more your mother can file for separation and then divorce.