I listed it as zero personal days and 365 fair rental days copying what the accountant did in 2016 after it was converted.
From the IRS point of view on this, if there was no personal use days, and all 365 days of the year were "fair rental days", that means the property was never classified for personal use of any type, for even one single day of the year. Therefore, there's no way it could have been your primary residence. Then, if you did not take depreciation as required by law, that's another flag for the IRS. These "flags" generally start flapping in the breeze the tax year you report the sale of the property.
Based on the information provided now, you don't just have a problem here. You have a really big problem that's going to be screaming at the IRS for attention - if it hasn't already.
Seek profession help yesterday, if not sooner.
