2 of the requirements to claim head of household
1) a legally related dependent - you are not (in your situation that would likely mean you had a child and he's the father)
2) the legally related dependent used the taxpayer's household, for which taxpayer paid at least 1/2 the cost, as their principal place of abode for more than 6 months.
as to who can take the deduction for mortgage interest and taxes, who paid them? there is no such rule that says the one that earned the most gets the deduction
