What you describe might be herpes, as the symptoms are certainly similar, but it could be an allergic reaction or something too. It's a good idea to get a doc to look at it, I think.
You might try one of the over-the-counter cold sore creams available (Abreva is one) and see if that helps. (Cold sores are a type of herpes, as you are obviously aware.) Meantime, try not to touch them and keep them clean and dry. I wouldn't use a chapstick, as that could spread them more,if it's herpes.
Don't beat yourself up about this.
An estimated 50-80% of the general population has oral herpes, usually caught in childhood through non-sexual contact with family members and friends. A majority of people who have herpes don't get symptoms for long periods of time or ever, so it's not out of the question that you could have had it all along but only just started getting symptoms now. Symptoms are often brought on by things like stress, sunlight (UV) or a stressed immune system, as well as other factors.
If your doc isn't sure what it is, I'd suggest you get a blood test (be sure it's type-specific). You might also get a swab culture done, but you might want to wait if they come back, when the symptoms are in their first 24-48 hours. Beyond that time the results are often not accurate and false negative results are common from the swab tests. The blood tests, on the other hand, tend to be more accurate after 3-4 months since first contracting it.
It's a good idea to be cautious about this, whatever it is, at least until you find out for sure what it is. So try not to touch it and be sure to wash your hands afterwards if you can't avoid it, before touching yourself anywhere else.
I hope that helps, even if it's not what you hoped to hear, I guess. Let us know how you make out.