Welcome to Just Answer and thanks for your question. Please don't hesitate to see your physician. We see everything every day, so it won't be anything that hasn't been seen before, and won't even raise an eyebrow. If pus came from the lesion, it probably was not herpes, and herpes typically doesn't involve a sac. Herpes are small clear fluid filled blisters. It sounds more like what you had was a cyst which was infected. The problem now is that it is very subject to risk from further infection and you may need antibiotics. Your physician can also run a blood test to see if you have herpes. If you do there are medications that help prevent an outbreak.