I had a similar experience. I had a bad experience getting my LP in the first place...took two docs multiple attempts over a two day period before they were successful (long story)...but surprisingly, I felt fine two days after the LP. So I went to the beach with my brother and nephews...and spent the day in the water having fun. And when I got home, I had a screaming headache. By the next morning, whenever I tried to sit up, I got bright flashes and the room would spin and my head felt like it was imploding. So I ended up flat on my back in a dark room for about 3-4 days after that before I could get up without a headache. Caffeine helped...Tylenol helped...but nothing but laying flat and resting cured it.