Herpes rarely goes from the genitals to the mouth, but the timing is really good for syphilis, though the symptoms don't sound exactly right for that.
You should go today to get them checked out, and cultured for herpes and get a syphilis test.
Let me know what happens. Don't let them visually diagnose you. Insist on actual testing. If they do a herpes culture, make sure it's a type specific one.