Some of the newer computerized machines have a "Stop/Start" button. While this is mainly designed for machine embroidery, it can also be used for regular sewing and quilting. As a matter of fact, when took a machine quilting class, the instructor suggested that using the stop/start gives the user a better stitch than can be achieved with the foot pedal. While this might not be an "inexpensive aid" as you requested, it might be a possible solution.
I, too, commend your determination to keep on quilting. Good for you! Please let us know what works out for you.