Exercise actually creates endorphins, which are the natural pain relievers in your body. Once you happen to make more endorphins, will certainly have less myofascial pain at night. With this, your natural rest cycle gets restored.
Also, to be able to sleep properly your body may want to burn some physical energy during the day. In getting out of the downward spiral you really need to begin with an incremental program of regular aerobic exercise.
If you happen to become deconditioned by the chronic myofascial pain you have, in the beginning, walk just to your gate and back. After just a few days you can very well walk out your gate to the first lamp post and back.