I was quite regularly experiencing vertigo attacks, along with tinnitus and acephalgic migraines (where you get the symptoms of a migraine attack such as auras etc, but without experiencing a headache). They've all stopped since I started taking hormones, so presumably they were the result of hypogonadism (abnormally low sex hormone production, something I've suffered from all my life). I was experiencing a lot of stiffness in my neck, and back pain, as well (which now looks like it was due to my spinal vertebrae starting to crumble - another problem commonly associated with hypogonadism). I've heard of other people with a history of DES exposure and signs of hypogonadism experiencing similar problems too. It seems that the brain, along with the rest of your body, needs either male-typical levels of testosterone or female-typical levels of estradiol to be present, in order to maintain it in good working order.
From what you say, your symptoms have only appeared since you had the chemotherapy. How do your current E levels compare to what they were prior to you stopping when you had the chemotherapy? Presumably your T levels are now low to nonexistent, if you've been on female HRT for 6 years. It's possible that your E is significantly lower now than it was prior to the chemotherapy, and perhaps that on top of the 3 month break is why you're experiencing these effects. When he restarted you on E, did your doctor cut your dose by any chance?
