Hi!
Really, it's impossible to provide useful advice as each case each unique.
I've been dealing with Chiari for over 25 years. Despite it having been very disabling for many years and excruciating pain the first few years, I've never taken medication or had the surgery (it was not possible in my case due to the fact that I have several conditions making surgery very complicated as to be dangerous). Still, I may not have had the surgery had I'd been a 'normal' case, as I am not convinced, from my research, that it is useful in the long term. I would not disuade anyone from having the surgery because, theoretically, one would assume that lowering the 'intra-cranial pressure' should help the symptoms if not 'cure' (that is, resolve) the condition. But it's just that, after the surgery, some people are worse and most people have the symptoms recur. I decided that the best thing to do was to 'accept' my condition and live within the new limitations; which was not easy for me as I was a high-achieving person who would normally 'push the envelope'.
I long ago abandoned the idea that I would become miraculously 'my old self' (use to run marathons, lift weights, work out four a day until I was 39 and was first afflicted with Chiari symptoms). But now, by being careful of what I do, I can live a life without having the worse of the symptoms.
What I highly recommend for pain and other symptoms is acupuncture. You might have to try three or four different acupuncturists before you find one that is right for your situation (usually can tell with a couple of weeks of treatment). While massage and other therapies provide temporary relief, acupunture best deals with the neurological symptom; and, while it's not likely a cure, it does deal directly with the nervous system which is what is most affected by Chiari syndrome. In my case, over a period of about six months of treatment, it reduced my pain by about 90%. Since then, I've only had treatments when I worsen my condition by doing something which is too much for me -- mainly lifting.
I wish I could be more helpful. It's a very frustrating condition because, one looks normal but, inside, things are very wrong. And, specialists will all look at the same MRI (I've had many over the years); all agree on the Chiari; and most often disagree as to what might be causing the symptoms. And, even if there is agreement, remember decompression surgery is not a cure but just another way to deal with symptoms -- as are drugs, acupuncture etc.
My sincere best of luck!