Hello. I was diagnosed with Chiari back in Feb of this year. My diagnoses and subsequent surgery was a whirlwind. From time of diagnoses to being under the knife was 3 weeks.

My NS did say that Chiari is something I'll have forever. There is no getting rid of it. It's a defect that we're usually born with. I can handle that.
But he did say decompression surgery gives relief.

I had the decompression surgery and a laminectomy of my C1 and C2.
I'm 6 months post-op and while my symptoms are returning (I probably did something to myself) I felt great up until this point. My headaches were gone. I was able to concentrate and actually have a life.

If your doc isn't discussing options with you, I'd seek out a second opinion. It is a manageable thing that you don't have to just deal with.

Good luck!