Hi Cheryl
yes, I agree that it is likley the effect of a rapid switch of meds without first withdrawing the first correctly.
I just looked it up in Your Drug May Be Your Problem and the symptoms fit with too fast withdrawal
the rule of thumb for "psychiatric" meds (I hate that description

) is to go down 10% every 10 days or withinn that range.........I know some docs say go down a third every 3 days
Try to encourage him to drink lots of water and also maye take Epsom Salts baths which helps with the detoxing (2 cups of epsom salts dissolved into a tub of warm water)
Hot freshly squeezed lemon juice also helps (half lemon in a cup of boiled water, with or without honey)
I sympathise as my son had awful withdrawal symptoms from his med cocktail even tho we did do it slowly.......some people's bodies are just very hypersensitive
anyway, I do hope Luke feels better soon and that things will stabilize. He really has been thru a lot lately, as have you (((Cheryl & Luke)))