I did a search on Theanine - it's used for PMS, anxiety, depression and it helps you relax and de-stress.....this might be your problem.

Also, I don't know if your aware but if you have MS Melatonin is not something you should take. The link is to the Rocky Mountain MS Center and Melatonin.
http://www.ms-cam.org/z_wrapper.php3?z=26