when did you enter the country with F-1; which country are you from; how did you earn enough to have to file a return for the earlier years; do you have an ITIN or SSN ( which one? ); if SSN how did you qualify for it; how did you end up getting the AOC since it should have asked for SSN; are you here by yourself or are you married and if so to whom ( US citizen/US Resident/ US national / Resident Alien for tax purposes or a Non-Resident Alien); etc. etc.
Generally the fact that you filed wrong type of return is fixed by amending those returns -- filing 1040-NR -- this may also mean paying back some refunds ( paying additional taxes + interest ); the AOC ineligibility would mean you have return all that monies as part of the amended return.
Please answer the questions raised , as this may lead to a more specific answer and the steps you need to follow to bring yourself in compliance. It is always better to correct errors before the IRS finds them ( sometimes they may not ).