Out of curiosity, has your doctor considered prescribing a medication that might calm the tremors? There are some. I know that propranolol can, for some people. I take 40 mg of propranolol (for something else) but have no side effects.

When I was on 1,200 mg Lithium I had terrible tremors, but wasn't taking propranolol back then. On 900 mg Lithium, I was taking propranolol and had virtually no tremors. I don't recall any tremors on Abilify, but can't say others wouldn't.