When you are cancer free for a bit (hopefully your nodes will come back clear and you won't have to have rads and chemo) and you're healed - maybe look into physio for your neck, and eventually lymphatic massage.

I also had a bit of acupuncture (too early for you to even consider this - BTW) it helped get the fluids and blood moving in the area. I am still numb (somewhat) and a bit tight 4 years later. I doubt the numbness will ever completely go away but it does improve and the tightness will minimize over time.

hugs...