15 weeks after neck/ lower face lift w/ removal of the SMAS, tightness is increasing w/ difficulty swallowing. Is this normal?

Tightness and some mild discomfort is common following facelift, but it sounds like your response to the surgery is unusual.  I would recommend revisiting the issue with your doctor and  consider seeing a pain specialist or neurologist.  There are several non narcotic medications that might be helpful until this resolves.

Tightness and discomfort in the neck and around the ears is very common and can last 2-3 months after a facelift. However, the symptoms you are describing are what I would consider out of the range of normal. Furthermore, your symptoms certainly should not be worsening. If you aren't comfortable with your surgeons recommendation I would suggest you seek consultation for a second opinion with a board-certified facial plastic surgeon or plastic surgeon who has extensive experience with facelift. Sounds like you have been miserable. I hope you start feeling better soon. Good luck!