Yes, you should see a tax professional right away.
Generally, you can allow family to live in a home you own, and they can contribute to expenses, without having to report it as rental income. Of course, you can't then deduct expenses (other than the usual provisions that allow you to deduct all your property taxes and mortgage interest on one main home and one second home.)
Also as TaxGuyBill raises, if you do not charge fair market value rent (the same rent you would charge to a stranger) then you are not allowed to deduct rental losses at all. (You can deduct expenses up to the rent paid but you can't deduct additional expenses to show a loss.) And then the fact that you share a house with one of the children makes it even more complicated.
Unwinding this arrangement correctly (considering depreciation and possible non-allowable losses) will probably need a tax professional.
At that point, once you have decided that your present or amended returns are indeed the true and accurate returns, and were not created to hide a loss to show more income, then you could certainly use them in a loan application. Your focus first should be on determining the correct tax treatment for this relationship and correcting your tax returns if needed.
