Hi - i am not sure there are any structures in the neck that aren't innervated.
To me it sounds like you have sprained your neck - a 4 week recovery is about right for self-healing but if it is without proper treatment, it is likely to be a less-than-optimal repair and so likely to happen again (as it seems it has again).
THe pain in the neck is likely to be the painful, innervated structure. The head pain is likely to be referred from the neck, particularly the upper neck. If the problem is in the lower neck, the upper neck can be affected by the muscles that cross both regions from the thorax/shoulder below etc.
My recommendation (as with the others above) is go see someone about it. Not likely to be a nasty problem but what if it is??