Tax Year Prior to 2020: Single Member LLC Filing

The past two years my CPA had filed my taxes using form 1065. I was informed by an IRS agent that since I am a single member LLC and my husband is not a part of the operation of my business or listed on my LLC documents we do not have file as a partnership. Although for 2013 and 2014 my business taxes was filed on form 1065, can I now just do 1040 along with my personal household taxes? or once you file as 1065 you can't change another tax year and file differently?