Dear Katy, I am sure this is a "disease" that can happen to any artist :) sometimes it just means that you need a time for rest and it is also important. If you see that it takes too long I would suggest you to do couple of very simple things to "awake" again your creativity:

1. Visit a museum or look through the art books on work of others.
2. Try to paint your feelings instead of painting specifical subjects.
3. Paint outside, or paint from nature - flower, butterfly, whatever catching your eye.
4. Take a small scetching book with you - scribble in it whatever comes to your mind without thinking how good or bad it looks, just let it go :)

I hope it helps!