Are you rejecting yourself because you have herpes? That's where you start.
"But what if they reject me?" The experience of being rejected is really a state of mind ... and if you disclose from a place of courage, self awareness and presence, then you can see that talk as successful (regardless of whether you are "accepted" or "rejected"). You might feel afraid to disclose to someone, but could that be because your connection with that person is special? If so, then you can choose to focus on the good things about your connection, rather than the fear of losing them.