I did end up donating blood last night. Woo! Savin lives! :) I felt fine afterwards, came home, stayed up til 11 PM, went to bed. Left the wrap on, because I was asleep when the "leave it on at least four hours" thing expired. So, just slept with it on. Woke up, still felt fine. Went and took the wrap off my arm (puncture started to bleed a dots worth of blood, then was over). Came upstairs to get a bandaid to put on it, started to pass out in the bathroom. Luckily only blacked out, kinda collapsed on the floor. Got up, stumbled to the couch in the living room, waited a minute for the woozy feelings to go away, then went to the kitchen to get a water bottle. Started blacking out again, went back to the couch and sipped the water bottle til the water was gone. Ended up lying there for about half an hour waiting for the light-headedness to go away and the ringing in my ears to stop. What a way to start my day.