If you are the lender, you do not issue any tax forms because you are not a bank or professional lender, because you said this was a personal mortgage. You are still required to report the interest you receive as taxable income, but you do that without any other reporting forms.
If you are the borrower, you do not issue any tax statements to the lender.
(A bank would issue a 1098 to report mortgage interest received, not a 1099-INT.)
