Headaches when lying down is a bit of a red flag. It might just be a headache, that is a primary headache, but it can also be a sign of too high pressure within the skull, intracranial hypertension. This can be caused by a number of things. Statistically chiari malformation is the most common cause but there are others, like tumors aneurysms etc. Intracranial hypertension can damage the optical nerve and cause blindness or vision loss if left untreated plus that the underlying cause can cause other damages.
So go to a doctor and check this out properly. It needn't be serious but better safe than sorry. The test to take is a brain MRI or a ct scan. Alternatively an eye doctor can also see signs of this in the eye bottoms, since the eyes are really part of the brain, although an eye doctor can not tell you what the cause is if signs are found. The mri or ct shows more.
Go check it as soon as possible but try to stay calm and objective about it.
Good luck!
Hello to you and Your Pain,
I have simiar problem and am sure it is nerve damage.
Chiro has helped in the past and Looking for a good one as I am now in a different area. Heat Pad and Get yourself Comfortable at Night. That is all I can do for myself at Present. I have read over 100 blogs on here back to 2007 and The Most I have to Learn is Keep your Money and Try to Learn to Live with it if A Good D.C. can not get you some relief Be Well .. jmg
Could be vertigo, do you get dizzy as well?