Hi and welcome to the Chiari forum.
U r soooooo right u need a Dr that is well experienced with chiari...we do have a list of Drs compiled by the members here...it is not meant as a referral , so u do need to research the drs but it is easier to have the names to start with.-
http://www.medhelp.org/health_pages/Neurological%20Disorders/DOCTORS-LIST-FOR-CHIARI-SYRINGOMYELIA/show/1062?cid=186
There r a few Chiari related conditions that may be causing ur issues one is ICP intera cranial hypertension....excess CSF fluid and could be y ur Dr tried the Diamox it is used for ICP .
The other possibility is POTS- if u can , take ur BP when u stand , sit, lie down and see if u have positional changes...even if ur HA's change with that...
Not everyone with Chiari will have all the symptoms, or all of them at the same time, it is a condition where the symptoms cycle....so keeping a journal may help too.
"selma"