WOW!!! You scare me! Do you have any symptoms? Like fatigue, jaundice, itching, pain? You are probably alright, if you only did this once and have no symptoms. But take it from someone who had a liver transplant, from use of acetaminophen. Don't do that again. I won't even touch Tylenol. A group of doctors in Indiana are trying to have it banned. Trust me it is dangerous alone...but with alcohol it is lethal. If you suddenly have extreme fatigue, go to your doctor. Usually the first sign of liver damage is fatigue if it is minor damage. I do feel you would know if it was major, jaundice, pain. But it wouldn't be a bad idea to see your doctor. :o)
Since this has been left open for a while I'll take a guess.. I've done some reading up on the net as well.
First off you need to stop doing both the tylenol and the alcohol...to prevent further damage. You may not have to go to the hospital, but seeing your doctor is a good idea.