Hi Christine
Yes I have, but only as part of a horrible silent migraine about 3+ years ago. I was never a headache sufferer till I entered perimenopause but boy am I getting payback now!
I really worried at the time but I hadn't really skipped a period at this point so never really associated it with hormones.
Can I ask are you desk-bound as a job, you say you spend a lot of time on the phone - do you have a headset for this? The reason I ask is that I had an improvement in some of my symptoms when I saw an osteopath. Neck strain can cause lots of issues with headaches as the nerves and muscles affect the head. Cradling phone between ear and neck was my thing, trying to ruddy multi-task haha. Invested in a headset so I can talk and type.
Obviously this experience has been mainly about headaches, but brain fog really hit me and I worried it was something serious. The HRT has helped that, I would have a name on the tip of my tongue and run out of steam as I was getting to it!! It does sound like your GP is at least open to considering it is brain-fog related but he/she is right, if the symptoms persist once the HRT has settled in then keep asking for help.
Xx Mogg