Just to clarify one point, reference opposite side versus opposite muscle.
Example:
Left Bicep is opposite muscle of Left tricep.
Left bicep is opposite side of Right bicep
Cervical strain is very possible, can easily last 3 years, as is a definitive diagnosis that is not an issue on unknown underlying cause.
Most people, and a large % of the medical community, grossly overlook the importance and severity of soft tissue injuries.
1 major factor is uneven muscle development and overstress to one side, or muscle group.
Injured muscle never gets redeveloped to equal opposite muscle and/or opposite side. This creates multiple avenues of stress to the muscle skeletal system, in the specific area, as well as any other areas that now compensate.
Muscle strengthening and tone, as well as eliminating compensation habits, are important.
Equally overlooked is the extreme importance in ergonomics in all activity, not just desk work.
Cervical strain is just something say when they don't know whats wrong. They diagnosed me with it one time.Yes its possible for a neck injury to last for over 3 years, especially with something hitting you like that. Have you been seeing a Doctor regularly since this happened? Get the MRI report and post it on here so we can take a look at it.
Even if your MRI doesn't show anything you still need to have your symptoms treated. Pain Clinics are full of people whose MRI's and X-rays don't show any abnormality, that doesn't mean that there isn't anything wrong, it's just not identifiable. You still have the pain, it has to be treated.
What kind of Doctors have you seen, and what other diagnosis have they given you? Your right not to buy everything they tell you, don't, protect yourself. Sounds like you've been going through a pretty rough time, hope you feel better. I think you see a Neurologist, they deal with a lot of the symptoms that you have.
Take Care