For me it went on for several months (maybe a year or so - I can't remember) but I was/am a "late finisher" if the average menopause age of 51 is to be believed. I am now 56. Been on continuous HRT since January and my last official bleed was August 2023. I assume I am officially post-menopausal now but having been on HRT for 3 years (sequential before I moved to continuous in January) I don't "officially" know.
We are all different and as unsettling as it is you just have to let your body get on with it and do it's own thing. Hang in there X