Extreme Dehydration?

This was a first trip. I'm less concerned with the "mental" effects that I experienced, since I was 'expecting' an 'altered' mental state. What I found 'distracting' were the physical effects:

....Started out with noticable tearing (that's 'tear' as in water from the eyes, not 'ripping').

....Then a heck of a lot of huge yawning which made the eyes tear even more.

....Then I must have gotten up 3 or 4 times during the trip to urinate, and the amounts were copious, I mean really to the point of "shit, Niagra Falls, something's not right here..."

....Finally, When I got up the next morning, on a hunch, I pinched some skin on my neck and it stayed squished! No, not residual hallucinations, but a sign of extreme dehydration!

Has anyone noticed this? Could it have been dangerously high blood pressure pushing out the water through my tear-ducts and bladder? Any one else notice such extreme dehydration? High blood pressure?