Good luck on your surgery. The neck dissection sounds daunting but it really isn't that bad. You are numb and stiff post op, and you may have shoulder issues for a bit. I jumped right into physio after and my shoulder is nearly perfect now, but this takes patience and time, and determination to do your exercises.

Ultimately it is a small price to pay for peace of mind. ;o) You will get through it ok.

hugs. and good luck - read up on the surgery and what to expect.