Married filing separately?

We are in the process of negotiating a separation agreement. We have been separated since Sept 28 2013 (a date that has been mutually agreed upon but nothing has been finalized since we have not completed a separation agreement). I am losing my health insurance coverage effective Nov 28 because my estranged husband has been laid off. I am attempting to acquire my own health insurance, but am unsure what income I will have to claim for 2014. I have my own job/paycheck, but he has been giving me some support money (an amount chosen by him). He plans to file separately for 2014 (and so, then, must I), but I don’t know if I have to claim the money he has given me as income for 2014. I don’t know if we will be legally divorced by Dec 31, but hopefully at least the settlement agreement will be finished. At this point, I want to apply for subsidy assistance under the affordable healthcare act (for just Dec 2014) and will have to state my projected 2014 income. Do I have to count the money he’s given me?

If it matters, I will not be able to file as head of household after the divorce because my ex will be claiming our 21 yr old son as his dependent while he’s still in college.

Questions about the application process for this subsidy should be directed to www.healthcare.gov. Alimony is treated as income and taxed as such, however I am unfamiliar with the application requirements for this subsidy. The application may define “income” and explain what needs to be included, but to be sure I would contact personnel at healthcare.gov.