To start, I recommend seeing a chiropractor, this appears to be signs of subluxations of vertebrae (meaning mis-aligned verterbrae) and as long as they are "out" you will have this pain.
I would also use a heating pad until you can get in to see one, some deep heating type cream, and soaking in Epsom salts. I would ask the chiropractor about deep massage as well.
Without any other symptoms, it does appear that you have a muscular/skeletal problem.
Take pain relief as required. Apply heat to the area, but if this makes it feel worse, then apply a cold compress.
It is surprising that the smallest twist to pick something up can set off back problems. You can also purchase anti-inflammatory gels to apply directly to the area. Anti-inflammatory pills do not suit everyone and can cause stomach problems. If you do purchase any, make sure you take them with or after food.
It is not an urgent matter, but making an appointment to see your doctor will give you a more accurate diagnosis and whether you do need further investigation like having xrays or other imaging to see if there is any degenerative diseases like osteoarthritis.
Keep warm and keep out of draughts. You would be surprised how a being or sitting in a draught can cause neck problems.
When you need to pick something up, do so by bending your knees and keep your back straight. If an item is bulky and heavy, get help to lift and move it.
Neck and back pain can occur due to other reasons and not just bone problems (degenerative diseases of the spine). Hence it is wise to get a doctor's diagnosis.
I do find that having a massage does help to relax the muscles that are causing spasms, but this does not cure any bone problems.
Even with bone problems you will experience good and bad days and even the severity can fluctuate within the day.
Hope you get some relief soon
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