I am so sorry that you're having such a rough time, especially when you were doing so well. I can't tell you how many times a shunt was mentioned whenever my headaches returned and my vision suffered, but then they would up my Diamox and do an LP and it wouldn't be mentioned again, because everything settled down.
I know the mention of a shunt is enough to cause anxiety, it's a big thing. A shunt is a last resort when they've tried everything and it hasn't worked, so please don't be too despondent just yet, as the upped medication might be all that was needed. Let them give that a try first and fingers crossed it does the trick.
We are ALL here for you, you aren't alone and we will do our very best to help you through whatever your doctor decides.