I just e-filed my returns through TurboTax and then found another 1098. I had forgotten that our mortgage changed companies last year. Is it possible to fix this?

Open your tax return in TurboTax, add the additional form 1098 and see if it makes any difference to the refund or amount due.  It may not make any difference. If it does decrease your amount due, or increase your refund, you can amend the return in TurboTax.