There are two issues here.

1. You are considered legally separated for tax purposes (See IRS Pub. 504), if you haven't lived together for 12months.
2. You can exclude your husband's income from your tax return.
3. " " when apply school aid if you do not receive money from him to suppor you or your children's living here.
4. If you file as Head of Household, your husband has to file as single, if he is a US citizen or has green card.