Self-employment Teacher Consultiing fees paid as stipend indstead of 1099

I am a teacher and I have a consultant business. Consulting Services provided to my district are not listed on form 1099; but instead, lumped into a stipend payment under categories (i.e. I do seminars and its lumped under 'teach workshops' on my pay-stub). Since this income has already been taxed through my employer, linking reporting it on Sch c business income would cause double taxation issues, as it has already been taxed at a fairly high emolument rate. Additionally, since it is the only type of business income generated in 2018, not including on Sch C would result in -0- income for the year. How do report this?