Could be just the shock of the amount of bleeding. Like you could have had a "Oh no, crikey, this is more than I thought" and your brain had a little panic. Or I could be talking absolute rubbish, I honestly don't know, but I'd guess at that due to you not having a real phobia of blood. A couple of questions, had you eaten and drank well that day? What was room temperature, your temperature? Any current illnesses? You seem a level headed guy. You've done everything right, by the way. Disinfect, breathe well, band-aid, get up controlled - good work. I wouldn't go out of the way to make a new appointment, but if you see a doctor any time soon, just mention to him what happened. It can't hurt. Most of all, I hope it doesn't happen again, pal!