If you each of meet the requirements to file as head of household, then you could each use that filing status but because you are married, you have the option to file as married filing jointly regardless of the fact that you dont live together.
Married filing jointly is the best filing status option available because
you get the lowest tax rates, highest standard deduction, and the best tax
benefits of any of the filing status options, including head of household.
Please refer to the following FAQ to learn more about the requirements for filing as head of household. https://ttlc.intuit.com/replies/4206137