I don't remember you saying what type of tire, but unless it's a really good tire, it may well be time to look for a new one. If it was me, I'd go over it once more, bending it inside out and see if I could find what's causing the hole. Barring that, yeah... new tire.
don't know where you are, but check for a Performance store in your area.
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"There is no greater wonder than the way the face and character of a woman fit so perfectly in a man's mind, and stay there, and he could never tell you why. It just seems it was the thing he most wanted." Robert Louis Stevenson