Firstly, accept my heartiest condolences on the death of your husband. May departed soul live in peace.
Secondly, please be informed that your story is the story of almost all the households in India and you are not alone in this situation.
What I need to advise you as per my experience is -
1. Don't take initiative to file case against the bank.
2. Let the bank take legal recourse.
3. On receipt of any notice from your bank, hire a lawyer practicing in Debt Recovery Tribunal and send appropriate reply to the notice.
4. Keep hunt of a prospective buyer and sell the property with the help of lawyer and bank at appropriate time.
5. Take care of your life, health more than the bank loan, worst situation is that bank would take the possession of the mortgaged property and auction it and it would take time by the time you would learn how to overcome with the situation. Life is more important than loan.
6. A good Debt Recovery Lawyer would save you.
7. You have the Will to settle the matter, you would get the way.
8. Don't come in contact with bank and ask them to take legal recourse and meet them with your lawyer only.
9. Sometimes bank officials put unnecessary pressure to withdraw the money but when they are in the court, the Judge hear both the parties and waive /reduce the interest and other unnecessary hidden charges.
10. Be happy. Time will take its own recourse not more than the mortgaged property.