How to handle controlling patients?

What do you mean by things taken care of? Do they want for you to make the funeral arrangements, cleaning their house, giving away assets, etc.?

You say they are "a dying person", by that do you mean they have a terminal diagnosis and a few months to live? If so I would do a little therapeutic fibbing, assure them that you are making phone calls and arranging for things to be done as soon as possible but these things take time to arrange.