Do I have to file my 1098?

No, If you mean do you need to enter Form 1098 Mortgage interest that you received on your tax return. It is optional.

If you mean you received mortgage interest from someone you issued a mortgage to, then you only need to issue that form if the interest is over $600 for the year and the mortgage interest was received in the course of your business, per the IRS instructions for Form 1098:

You posted this question in the Education section. Do you have a Form 1098 for mortgage interest or do you have a Form 1098-T for tuition?