The diagnosis of MS can be long and disheartening. At this point, it likely is not, but these neuro issues are so complex and hard to figure out, and whatever the outcome, it's exhausting having to push on.
Have you seen a neurologist? Had mris and a neuro exam done?
Sometimes it's helpful to see other specialists. For instance, see a physical therapist for a full work up to look for weakness. If you have any vision issues, have your gp or optometrist refer you to a neuro opthalmologist.
Until the imaging and test results are textbook, (for ms or something else) it often becomes a case of being followed.
You might ask at the fibro board whether pain on one side is typical; I have no experience with fibro at all.
MS neurologists consider weakness, balance, sensory changes, certain bowel and bladder issues, vision issues to be some of the more important ms-related symptomology. All-over symptoms, headaches, pain, etc. Are often ignored as red flags away from an ms diagnosis.