Maybe, your pdoc will gradually get you off Lithium and just use the Lamictal in time? I've been on Lamictal for a few years now (I am DXed with Bipolar-II/mild) and have found it to be very good. Before that I had been on Lithium (my brother has been on 33yrs now, and no problems) but I needed something with an antidepressant quality, so my pdoc suggested I give the Lamictal a try, in fact I'm down to 150mg's a day now. I like Lithium so much better than Depakote, Lithium allowed me to function and not be drowsy.
I think many of us with DXes sometimes have to go through trying different meds. in order to get the right fit, don't discourage, it will happen.
One thing though, if you are not satisfied with treatment and the pdoc, a change to a new pdoc can be key.
I wish you lots of luck and healing, welcome to PC.
Take care,
DE