After a session or two, I would highly recommend using stretching as an ADJUNCT to your soft tissue work, not as a seperate treatment.
You can train on it, provided the pain is tolerable. It is quite possible to begin to try and lean away from the pain causing more fascial tension/stress on other areas, which could lead into other problems. I would be certain to adjust the volume of your work and avoid lifts/exercises that cause much discomfort.