I'm curious if the lower dose of lithium has helped the hypothyroidism? My experience with lithium is that many of the adverse effects come being on much higher doses for a long period of time. I currently take 450mg twice daily and my lithium levels have never been high enough to cause issues. My PsychNP has been very conscious of insuring that I'm at a therapeutic but safe level with my meds.

I can't speak for valproic acid as I had issues from the get-go (muscle stiffness, too much sedation, etc) and had to stop after a week.

I've been on lamotrigine in addition to lithium and it has been a godsend! It was a heck of a merry-go-round to get to this point of relative stability.

I hope, in whatever form they take, you find the meds that are your godsend.