Nobody can tell you, including your psychiatrist,
how long this will last --
it could end tomorrow or last for months. Who knows? We react differently, and we react differently to different meds. And again, you might be suffering side effects of the Lamictal -- most meds for mental illness take a few weeks before they start working but side effects start right away. The only way to know for sure is to finish the taper off of a med before starting another. It's your choice, in the end.