Use your story. What you have done with your life thus far is a remarkable feat, and admissions and financial aid will view it as such. Don’t be scared to go straight to the top – ask to speak to the Dean, for example, if the underlings aren’t able or willing to help you. I got my financial aid family contribution waived by a yearly meeting with my Dean, where she checked up on how I was doing and reviewed my case.
Your story may sound fantastical to white bread America. If you find people disbelieve you, there are plenty of us willing to vouch for the hardships you have gone through to get to where you are.