i came off lithium, but it was so long ago i dont remember the effects (sorry cant be more help). i was SO glad to be off of it, i hated it so much. i got sick of not feeling anything at all like a zombie, and getting toxicity shakes all the time whenever i didn't drink enough water.
i always have tummy problems, so i might not have noticed that as a withdrawal effect. i do find peppermint is slightly helpful, rather than antacids. something in peppermint somehow eases muscle cramping/spasming that comes with emotional tummy probs. just some peppermint tea or even a little essence in water.
other than that, all i can offer is my empathy and hope that you feel better once you're on the other side.
ae