Good to hear that the medication is helping your mental focus, that much.
It is interesting that you mentioned dehydration since that is the first thing I wondered about when you mentioned unstable blood pressure. I don't know how often those issues are correlated but I have heard about hydration and/or electrolyte balance being associated with that, in the past. Given the sudden shift to hot weather, this would be the time of year when such things could happen. Of course, it is definitely something to investigate in order to make sure.
I hope that everyone gets closure around their health and feels more sure of themselves, soon.