All I can offer is my history and my subsequent cure. I'm sure you've read my threads below. For me, it was bracing, pure and simple. My shoulder and neck muscles were so tight that I was literally pulling my ribcage out of alignment. I found a very gifted massage therapist who was extremely careful with that area. Through lymphatic massage and shoulder and neck massage, I overcame my condition (after muliple years) with one month of sessions. It was worth all the money in the world to me, and I'd do it again. I still see her for one month visits to make sure I never go back there again.
It's all I can offer you on this. Have you looked into massage therapy? You need someone that is not only highly experienced but also intuitive.