Thanks for posting your query.
I can understand your concern.
Since the swab has come positive, it indicates that the ulcers near the anus are caused by hsv. The chances of it being false positive are less.
It's a viral infection of the skin, it stays dormant in the nerves , it doesn't enter the blood stream. In order to treat the infection you will need to take oral valacyclovir. That will resolve the infection of the skin. However, virus can still stay dormant in the nerves and can get reactivated in times of lowering of immunity of the individual.
I would recommend that you visit your doctor to get a prescription for valacyclovir which will heal the ulcers.
Hope I have answered your queries.