I wish you were not experiencing so many side effects. I have no personal experience with Pemigatinib, but when the early clinical trials were underway, some folks posted about their experience on the board. Try searching INCB054828 which was the name of Pemigatinib during the initial studies.
My own experience with my doctors is sometimes you need to push a little to identify better ways to alleviate side effects. If one nausea drug, for example, is not helping much, see if your doctor can suggest a different one.