You should state that you were a self employed independent contractor home care nurse, be proud of it. It has many advantages, you maintained your own clinical records and notes, billing, as well as provided care as needed for the individual and the family. You may use the client as a reference, with their permission, if they are still available espically if it was a long term case, and they can vouche for you. Also any collegues, other nurses, teachers, trainings or administrative professionals that you may have worked with or encountered in your career, might be willing to put in a good word for you. The transition from private care to agency is not that difficult, if the management is flexible and willing to work with you. Your experience is valuable, and the fact that you were your own boss, and supervisor, is something to be admired as well... it shows that you are a self starter and that you can have business savvy.
Self employed persons, should really examine their ability to take direction from others and work for a 'boss.' If they are more of a free spirit, I think most of them appreciate the help but prefer working without a manager, unless that manager lets their work be self directed. If you start to feel micromanage by them, or deal with a lot of bureaucracy, that is just added stress...It is, a signal that it may be time to go back to working for yourself.