That is a tough one. If you don’t want to give up the project financially or from a work standpoint, you are kind of left dealing with a tough personality. You can try to assert more boundaries. This will be challenging. For instance have updates only once a week. Do you have a clear statement of work? If so can you site some of these constant updates and changes as out of scope, hence requiring more money? I’m always amazed how good work gets when people realizes that further changes will cost more 