The answer depends on the amount of your gross income and whether your income from the sale of the property would be considered long term or short term capital gain. Contact an accountant or tax attorney, these issues can get too complicated for a message board.

Yes, consult a tax professional. The part of the duplex that you live in will be treated differently from the investment side which is a rental property. And you need to take into account rental income and depreciation of the rental property, too.