Right side neck pain. Muscle swelling?

I have been having occasional pains in the back of my neck on the right side for many days. While taking pictures today, I noticed that the right side of my neck is a little swollen. Which is not very clear to the naked eye. If you put your hand on the swollen area, no hard lump or gut-like thing can be felt. That is, there are no lymphnodes or tumors. I use two pillows to sleep, and work sitting all day. Another problem is that for the last 15 days there is a slight elevation in one place inside the mouth, there is no pain or irritation. An ENT doctor said it was due to smoking. There is nothing to fear. Quitting smoking will gradually return to normal. Currently I am taking antioxidant tablet. I wonder if it was for that cheek swelling? This neck swelling is something unusual or muscle swelling?