Can it happen without ever having sex?

Do you have an oily complexion? It's possible that you just have cist. I still get outbreaks similar to what you are decribing. For me it's basically acne that's under the skin and it causes the skin above it to bloat and it's hard and painful. I get the same thing behind my left ear quite often. They always go away, and I can ignore them for the most part.

I believe it's just a cist, but it never hurts to get a doctor to look at something when you're experiencing it for the first time. Once my doctor and mother told me what a cist was, I was able to diagnose myself and not be so concerned about them.

If you are worried about it, ask whoever you can trust (mother, grandmother, etc.). If they can't tell you what it is, just go to the doctor and get a little peace of mind.

I don't believe you have herpes but you may want to see a doctor

you can get herpes of someone's blood gets into your blood stream. recently a doctor in the Philadelphia hospital pasted on herpes to his patient through a surgery. Its a scary thought.

there are 2 types of herpes. HErpes simplex 1 can be caught by close skin contact, like kissing. Herpes Simplex 2 can be caught by sexual activity. Herpes Simplex 1 causes cold sores.
Herpes Zoster spreads by the air. Sneezing is a typical way of caching Herpes Zoster. it causes chicken pox or shingles.
So no, I don't think you can get herpes down by your vagina unless you had sex. Or unless someone was kissing your vagina. But if none of that happened, there's probably something wrong. Go see a doctor. Hope this helped :)