@Linda17, it’s great to have you join us, though I’m sorry about the circumstances!
I had an AVM in my dura mater (one of the outer meninges) in my occipital area in 2017 and I had headaches, dizziness and the pulse in my ear. I had mine “embolised” with glue.
Gamma knife takes quite a long time to fix your AVM but is the least invasive, least scary option, so if offered to me as an option, I think I’d have chosen the same as you!
Consequent to gamma taking a long time, I do think you’ll have some time to wait before the headaches go away. Equally, I don’t know what you’ll see at the six month mark other than to check no significant swelling going on. 6m does seem to be the point at which gamma starts to make a difference.
I know @JD12 had gamma, so will have more direct experience to share with you.
Wishing you all the best for an improving 2020!
Very best wishes,