Psychotically means in a way that belongs to psychosis — acting, speaking, or seeing the world as if the illness were in charge, or in a way caused by that illness. A person may behave psychotically during a very bad spell of the illness. People also use it as a loud ‘very’: psychotically jealous, psychotically neat. That stretch is informal and a bit theatrical; it does not mean the person is medically ill. Careful talk still keeps the illness meaning. The word is an adverb, so it tells you how something is done, not what kind of person someone is.