Burning vagina!!

Does anybody know what I can have this all happened after having sex with a hookup I got tested for std everything was negative I went to urgent care and they said I had vaginitis the metrogel helped but now it’s back I went to urgent care again then they prescribed me antifungal so I took that it helped but now it’s back idk what to do idk what I could possible have it’s burning inside my vagina is red!! My legs are burning too what is this