Welcome to HCM!
I have read your question carefully and feel that you need to see a neurologist
(as you have pain in head , neck, difficulty in seeing clearly), or at least a doctor in person.
Had I been treating you I would go for an MRI
brain to rule out any injury
to the brain. once this is fine, it will be wise to check neck by thorough examination and X Ray
neck, if there is any trauma to vertebrae.
You can take some pain killers and avoid moving your neck too much for time till you see a doctor.
only by thorough check up and investigation one can pin the diagnosis in your case.
Hope you get well soon.
Feel free to ask more questions regarding this .
Dr. Manisha Gopal.