switching from dilantin to lamictal resulted in seizure

Hi, I'm 45 yr old male and I've been on Dilantin for about 23 yrs with pretty good results. LAtely, due to some thinning bones, my neurologist suggested switching to Lamictal. Over the course of several months , i worked up to 400 mg/day Lamictal at which point we started to wean the Dilantin. Man, that didn't last long... I spent a week at 75% Dilantin, then moved to 50% for a couple days and boom... had a grand mal seizure at work. They brought me to the ER where they decided to fill me back up with Dilantin. So now I'm right back where I started from and suddenly the long-term side effects of Dilantin just aren't sounding so bad when compared to the complete loss of confidence that came along with having a seizure. I am not sure I want to even give Lamictal another chance at a higher dose... I am just not very optimistic at all about its effectiveness since I had one so quickly while coming off of the Dilantin. My gut tells me now that Lamictal is just not going to work. A shame too , I definitely felt mentally sharper with more energy when the Dilantin had been drastically reduced in my system. Lamictal does seem to have very few side effects. I see my doctor next week and I think she mentioned something about Depakote being the next thing to try.. and from my reading the side effects from depakote ( weight gain, hair loss, liver, pancreas, cognitive, energy, and even still some bone loss although to a lesser degree ) seem far worse than the ones from dilantin so i am just thinking of saying the hell with it and take my chances staying on the Dilantin even longer-term. Does anyone know if things like Fossamax can counteract the bone-thinning effects of Dilantin? Also, I am simply now afraid that gettig off Dilantin can itself be difficult to accomplish without having a seizure. Has anyone else had problems getting off of Dilantin onto other meds?