Frustrated

In the past few months I have had a root canal, had to have the same tooth re-root canaled and a second tooth has had a root canal. I have a constant feeling that my back molars are tightening and my bite is off. I went through a divorce this year and have people telling me that stress can cause symptoms like these. Is there another alternative to stress?

Yes there is another alternative to stress. It is relaxation! Have more fun and take vacations! :-)

First thing your bite may has been disrupted when the root canal procedure was performed as dental anatomy is likely to have changed, hence an alteration of your occlusal pattern achieved. Second, the feedback to your brain of local perception may also has been modified thru the process of RC therapy as removal of vital pulpal tissues usually lessens proprioceptive response.
What you need is a double specialist who can understand and practice both endodontics and occlusion.