Kim, This may be a little late advice, but I know that right after my surgery which was the removal of 2/3 of my tongue plus the lymph nodes in my neck, my doctor sent me to do some minor physical therapy. They worked on rotations in my neck and shoulders to help loosen them up for more movement and less pain. I only had to go 6 times, but there were enough exercises that really helped me. I don't have full range of motion, but I have a lot more than I did before the physical therapy.
Hope this helps!
kim