Exercise is always a good idea. Also, never underestimate the power of mental exercise, too. Have you done any obedience classes with Ellie? I think she would benefit trememdously from them. And besides, they are fun!
Here is a good article about retraining manic barkers:
http://www.clickersolutions.com/arti...nicbarking.htm
If you are looking for more suggestions, let me know. (Sometimes I have trouble differentiating between when people want help and when they want to vent).
Sorry that you are having such a hard time!