Filing your income tax return isn’t a negative thing for financial aid UNLESS you have done all of your work under the table in cash and there is no record of your income anywhere which would mean that your income tax return would be proof of income at FAFSA time. Of course, failing to file a return and pay taxes owed on cash income is a whole other legal issue that you don’t want to get yourself into.
So file your return. If you overpaid on income taxes you will get that money back. If you underpaid, you will have a chance to get yourself straight with the IRS. This also could make you eligible to claim the AOTC or Lifetime Learning Credit for yourself, and might position you to receive the stimulus money. @BelknapPoint might be able to help you sort out how that would work.