I can’t tell you what will happen, but I can tell you that you need to answer honestly. Was your father married to your stepmom in 2018? If so, he most likely was not able to file his taxes as head of household (in some rare circumstances, it is allowed, but it’s rare). If he was supposed to file as married (either jointly or separately), he will be required to amend his taxes in order for you to get aid. If you already received aid & the selection for verification happened after you were given aid, you may end up having to repay aid. Please don’t panic. Begin by talking with a financial aid officer at your school.