I would focus on getting this figured out first- cerebellar tonsillar ectopia -
and see how that goes.

for the rest - there are videos on you tube showing chiro/PT/bodyworker treatment for scoliosis so you could find someone trained to address that.
To me manual therapy seems better than wearing a brace of some sort..

I have slipping L4/5 and some c spine /upper back issues so I ordered an inversion table to see it that helps before seeking a new chiro.