Pain at the base of the neck is the hallmark of degenerative disc disease of the neck itself. Thoracic disc issues can cause pain at the base of the neck too but I have found that 95% of this pain is generated by the cervical spine.
Everyone will develop “arthritis” although I do not like that word for the degenerative changes of the neck. Most individuals do not develop significant pain regardless of the degeneration and the degenerative changes make the neck vulnerable to injury.
You do need a spine specialist to help sort out this dilemma.