I quit caffeine a year ago and I went through the same symptoms. I slept for 10 hours a night for 3 or 4 days and then my sleep cycle went back to normal.

After quitting, I realized that it amplified my anxiety levels in many social situations. It also put me in sort of a strange state-of-mind where my emotions seemed dull (I'm comparing now to then). In a way, it made me more of a compliant person.

I also can remember my dreams almost 3 or 4 times a week when I'm using not caffeine. I still drink it once in a long while, but it doesn't really start up the cycle anymore (I don't keep drinking coffee or pop on a regular basis).