Okay, let me share the things that I know. I prepared some documents to show that the financial situation of my sponsor had changed substentially due to unexpected events. These events must not exist at the time you applied for visa. These documents should be based on your situation and what you can come up with as a legitimate execuse.

What you need to prove is that you have an unexpected change in the financial situation of your family or your sponsor. For example, a member of your family needed a medical attention that took the substential amount of money from your sponsor, business closure of your sponsor due to natual calamaties or seizure by the government, losing of the job by your sponsor and things like that. Try to get documents from Nepal to justify those events. Have your sponsor write a TO WHOM IT MAY CONCERN kind of letter stating that he/she can not sponsor you any more due to these unexpected events.

I had a success on that but I lost my right to work due to the fact I transferred to another University where I again had to show the financial documents. That is why if you are planning to transfer, don't even try this because you will lose your EAD right. I hope this helps to some extent.