In reply to Bjartur í Sumarhús:
Where do you live? PM me if it's easier!
Is the chair in a car or behind a desk? You might find your chair and seating position is the reason there is no improvement. Can you work from a standing position or alternate between the two. When was the last time you had a work station assessment?
Your body has some incredible protective mechanisms, you'll know if you are doing too much. Perhaps try some ice therapy as well, 4 minutes on 90 minutes off. Either an ice pack or moving ice cube, both will give different responses.
You could ask your therapist to try Muscle Energy Technique if the trigger point is not working for you.