It's not an std, so relax. It could have been that your body didn't like the lube/oil and was attacking it. That would explain the tingling at your tip, and possibly swelling/white spots. Once you felt that, your genitally focussed anxiety kicked in, and is causing you to overreact to normal body sensations that would otherwise be ignored.
Relax. Forget about it. You've been checked, taken antibiotics under prescription, and most certainly didn't have an std to begin with. So, you're totally fine. Move on.