Have you tried physical therapy? My PT works not only on recovering range of motion in my neck and arm/shoulder but he also regularly massages my scar and breaks up the adhesions. I like to think of them like little plant roots that need to be broken off...kind of like ivy growing on my neck. Silly, I know but it works for a visual person like me!
I'm not familiar with neck fibrosis but it sounds worse than what I am dealing with. All I know is that I ws getting worse and worse-my neck wouldn't run and my shoulder and arm were getting hard to use. I kept mentioning it to my doctors and I wasn't getting much of a response beyond it's something I will have to work through. I finally insisted on physical therapy and it is doing wonders.
It's worth asking-no one is a better advocate for your health than you are! Good luck.