if I want to file a slander suit does it have to be in the county where the incident occured

You may have a case. You would need to prove the falsity of the allegations and also that the statements were published to a third party which caused you damages. I have successfully brought a case against a media company but every case is uniuque and fact specific. Reach out to counsel here in the state of Florida for possible contingency fee representation which means you pay nothing unless you win.