It doesn't sound like herpes at all. It could be fungal, or an allergic reaction, dry skin, dermatitis, etc. It would be helpful to take pics of it to show your doc at various stages.
It seems to heal with neosporin, which would suggest a bacteria, but it could also be dry skin that is being helped by the moisture of it.
If you do test positive for hsv1, my best is that it's a pre-existing oral infection. That's going to be the drawback with a blood test - it tells you what you have, not where you have it. Since you got oral sex, you would be at risk for genital hsv1. If you had an existing hsv1 infection, you can't get it genitally, but the blood test won't tell you where you have it. The next time you get symptoms genitally, see if you can get them PCR swabbed for herpes.
PCR swabs are far more sensitive than regular swabs, and can find herpes even without regular sores.
Let me know what happens.