Welcome to HCM!
After reading your question it appears that you have complaint of chronic headache and pressure and as you move your head, it feels as if fluids is moving.
From my clinical knowledge, I can say that you need to see a doctor, get your blood pressure checked and routine blood test
done. You may require a MRI brain and x Ray
neck to rule out any neurological problem.
The details provided in question are inadequate for any conclusion, however, for time been , for headache, I have seen good response to tapentadol
50 mg, as and when required, upto twice a day.
Please see a doctor, preffrably a neurologist
and get your self examined properly.
You donot have any other movement complain, or muscular weakness
, so, it is unlikely that there should be anything major to worry about.
Hope the reply is helpful, please ask more queries if you have.
Dr. Manisha Gopal.