This doesn't sound at all like herpes, which causes superficial blisters (with clear fluid) that then turn into superficial pustules. Think of herpes being "on" the skin, as compared with folliculitis, pimples, boils, and infected cysts being "in" the skin. You have one or more of these other conditions, not herpes. to confirm this and get advice about prevention and/or treatment, see a health care provider the next time it happens.
Good luck-- HHH, MD
Sounds like a boil to me. I get them all the time, it's a type of infection way underneath the skin and they're hard to pop until they come to a head. Sometimes they hurt, sometimes they don't. They tend to go away and come back in the same area. I think you can use Phizoderm over the counter treatment, but it's not genital herpes (or an STD for that matter) if it's not on your genitals. I'm not the doc, but that's what it sounds like to me.