Indeed. I have that as my number one advice and plan for tomorrow. :).
Beyond that, I will do my best to stay in school and find a way, until/if someone kicks me out of everything. 
Were you in school during 2014 for at least half-time for one semester?
If so, did you/your spouse claim the American Opportunity Tax Credit?
If there is that education credit on your tax return - that part of the tax refund (if there was one) probably should have gone to you since it’s based on tuition you paid.
you filed FAFSA wrong. You were separated when you filed, but you put that you were married. That was wrong.
Go to school, explain that you filed wrong and that you should have put separated. Provide documentation that you have been separated.
It sounds like you though that you were supposed to put “married” because of how you filed your taxes. Not true.
If your school and living costs are $24,000 a year and you can get a $10,500 loan, where is the other $13.5 k coming from?