You can't file as single if you are still married. You may qualify as Head of Household.
Head of Household
You may be able to file as head of household if you meet all the following requirements.
- You are unmarried or considered unmarried on the last day of the year. See Marital Status , earlier, and Considered Unmarried , later.
- You paid more than half the cost of keeping up a home for the year.
- A qualifying person lived with you in the home for more than half the year (except for temporary absences, such as school). However, if the qualifying person is your dependent parent, he or she doesn't have to live with you. See Special rule for parent , later, under Qualifying Person.
Qualifying Person
See Table 4 to see who is a qualifying person. Any person not described in Table 4 isn't a qualifying person
From <https://www.irs.gov/publications/p501#en_US_2017_publink1000220814>
