Help, my jaw hurts really bad!?

I recently went to the dentist to get a night guard made because I have TMJ. I also needed a crown. The dentist put on a temporary crown & it is significantly shorter then my original tooth. I have only been chewing on one side of my mouth (the side without the temporary crown) because the temporary crown fell out once & had to be put back on. I have awful pain on one side of my jaw (the side without the crown). I'm wondering if the fact that the temporary crown is smaller then my original tooth has caused my entire mount/jaw to be out of line & causing me so much pain, plus the fact that I have only been chewing on one side of my mouth. I go back to the dentist tomorrow to get the permanent crown & pick up my night guard. Any ideas what could be causing all this pain?