If this happened to me, I would switch to an all-machine binding method. Here is a link to a Youtube video that shows how to do this:
http://www.youtube.com/watch?v=wprg5vzkuGw
http://www.youtube.com/watch?v=7MRfA...eature=related
My fingers are odd lengths, so I have found that hand sewing of any kind causes cramping very quickly. Since I like applique, I have switched to machine applique methods and been very happy with it. Sharon Schamber has hand tremors, so she worked on developing her machine skills to extraordinary heights.
I guess my thought is that pain is an early warning sign that the activity may not be good for the individual body, so it is better to find ways of doing things that do not cause pain.