I've worked with such people from 1976-1980s. In the NHS.
. When I dream about her, I always win the battle
. She ruined many opportunities for better working conditions. I was fortunate in that my Boss as well as the other secretaries, were aware of her being a bully. (long story short). Now I would tackle the situation in a totally different way.
Is this woman in your section of the Company or does she liaise with the NHS? MayB ask the NHS itself for support? Liaise your HR with theirs?
Or take the bull by the horns: write a letter - " I am going through menopause symptoms so will require support as well as days off. Menopause issues should have been discussed at the Interview, therefore I expect to be able to continue with my job to the best of my abilities whilst undergoing The Change". There is nothing in my Contract of Employment stating that time cannot be taken due to menopause symptoms'.
And copy to as many in managerial positions as possible ;-). What's to lose ......... let us know how you get on.
"I've helped once, but that's it. Migraines can be part of peri-menopause (lay it on thickly) so hopefully you will be able to manage your work load in future".