Have sinus infection, randomly while txting felt some popping sensation or like throbbing in back of neck. Would that have to do with sinuses? Ideas?

Text neck. Text neck is the term used to describe the neck pain and damage sustained from looking down at your cell phone, tablet, or other wireless devices too frequently and for too long.
Neck pain. the neck pain is not related to the sinuses. It is a muscle pain from leaning over the computer and not sitting upright with good posture while working. Use some Tylenol (acetaminophen) or Motrin for the pain. Stretch the muscles. Use some ice to the area, rotate the ice with heat after a few days of ice. Should resolve in a few days. Good luck and feel better!