I felt that way (the hangover) very much when I was on Trileptal. I also get it when I take Klonopin before bed. I don't know what time you get up, but I have to be up at 6:30 every morning....and I've been known to take my meds at like midnight... so I try to make the effort to remember to take them earlier so they have more time to work in my system and I don't wake up feeling so groggry.