Lithium Toxicity

I got out of the hospital recently. I'm on lithium out of a few drugs I take. Was wondering if anyone had experience with toxicity. I found out that the symptoms of toxicity were nausea, shakiness, diahrhea, and vomiting. I was lowered on lithium and my thyroid was too low so I'm starting synthroid so hopefully things will resolve themselves. Doc said that adjustments would help mood stability and some other things.... but I've had some close calls with having diahrhea and have been using pepto bismul but that doesn't seem to be helping all of the time. any advice?

This is the info that's in my drug book:

Do you have a sodium deficit?
A sodium deficit causes more lithium to be reabsorbed and increases the risk of lithiium toxicity.

Toxic manifestations of lithium include nystagmus, tremors, oliguria, confusion, impaired consciousness, visual or tactile hallucinations, choreiform movements, convulsions, coma, and death.

Adverse effects with lithium:
Common : metallic taste, hand tremors, nausea, polyuria, polydipsia, diarrhea, muscular weakness, fatigue, edema, weight gain. These usually subside during the first few weeks of drug therapy.
Severe adverse effects: more severe nausea and diarrhea, vomiting, ataxia, incoordination, dizziness, slurred speech, blurred vision, tinnitus, muscle twitching and tremors, increased muscle tone.

Nausea may be decreased by giving lithium with meals.