Few questions: Did you finish the degree or do you still need to take classes? Also are you doing bachelors or masters?
If you have valid i 20 till april, you need to start applying to another univeristy as soon as possible because of the deadlines for most universities will be the end of Jan or Feb. Look into the International Students page on the university website and email the admissions assistant and explain in detail your situation and what you would like to do. Ask them the process in detail.
On a personal note when emailing please make sure your grammar is correct and also explain the situation correctly.