Believe me, you're not alone!  I'm having sort of a similar experience, although my seizures aren't changing (sp/cp/myo).  I'm at 600 mg Lamictal xr.  With this high of a dose my body decides to go crazy.  Double vision, dizzy, nauseaus, you name it.  The dr changed my prescription so I was just 50 mg less.  Sp all over the place!  After half a month I'd had it.  I put myself back on the 600 mg.  I see the neuro today.  I don't want my seizures to have a grip and escalate, but at the same time, the side effects are killing me.   We all have these battles and they don't get easier.  I've been there w/the whole seizures changing.  Last year, when I changed meds, my body/legs/arms would suddenly fly off and jerk.  The med I HAD been on was good at suppressing myoclonics and this medication isn't.  I never used to have the myo.  It's scary, frustrating, whatever words you can think of.  You're not alone!