If you did not live with your husband in 2016, you may be considered unmarried and be able to file as Head of Household.
Here are the requirements:
1) Taxpayer files a separate return
2) Taxpayer paid more than half the cost of keeping up the home for the tax year
3) Their spouse did not live in the home the last six months of the tax year
4) The taxpayer's home was the main home for more than half the year for their dependent child