How to correctly enter Ticketmaster ticket profits into Form 8949?

Hello all. I hope someone can help me .  I sold a few NFL tickets for a profit this past year.  Now I have a 1099-K from Live Nation Worldwide, Inc. It provides the "Gross amount of payment" which is significantly higher that my profit on the tickets.  I am unsure how to enter the ticket sale value, my cost and the 10% cut taken by Ticketmaster. on the internet folks suggest using Form 8949 which then apparently feeds into  Schedule D or just to use Schedule C.  I tried goin to Form 8949 but it has already been completed when I imported stock info from Fidelity and it doesn't look like I can add a new form or new lines to the existing form.  I am scratching my head over this.  Can anyone help?  Thanks a mil!