I become very physically dependent on meds, so when I go off of them it's always really rough for me. With my lamictal taper I was sick the entire time, but, as I've said before, it only got really bad when I was down to about 50mg. I'm happy I just happened to have three days off of work in a row, or I would have had to call in.
Anyway, so small decreases can cause issues.
If I was you, I'd just keep on going. You can do it. It's only bad in the short term. Once you're off lamictal, you're off. I didn't have an residual issues once I was off of it.
(Of course, now I'm obviously back on it. Lol! But that's just because I got PPD really bad and needed to go back on it.)
Anyway, good luck! Stay positive!