For 2018, you would be allowed to file as head of household if,
1. you were living separately from your spouse for all of the last 6 months of the year (7/1/18-12/31/18)
2. you paid more than half the cost of maintaining your home
3. at least one qualifying person lived in that home with you, usually a child dependent who slept in your home more than half the nights of the year.
Your spouse would file as married filing separately, unless your spouse also provided a home for a qualifying dependent.
It would not be the first time, or millionth time, that financial aid was wrong about income tax matters.
See IRS publication 501 https://www.irs.gov/forms-pubs/about-publication-501
