I'm going to ditto Christine and add a bit more - The swelling is a build up of lymph fluid because they have removed a major pathway for lymph drainage. It does get better in time. Massage does help, but I would hold off on that until you are "scanned and cancer free" I would not massage an area and push the fluid into circulation if there is any chance the cancer is still there.

That said numbness may be permanent or at least very long term - they cut nerves and muscles. The nerves take a very long time to heal - if ever d muscles for me are always a bit tight on my neck and I'm three years out (more actually) hugs.