How is your head/neck/shoulder posture?
Is head forward of the body, shoulders hunched or rolled, uneven?
Do you have neck and arm tension?

If you aren't seeing any improvements with that therapist try one with more experience.
Does PT check for trigger points? tiny super sensitive knots in the muscles- those must be released before any other muscle/fascia work will be helpful.
a easy clickable chart to locate TrPs-
http://www.pressurepointer.com/pain_reference_chart.htm