Found you, thanks terry.
Brickie about the hypertension - your experience is quite different from mine and I have no medical background, but - yours sounds like classic PIH and it is common to swing from low to high BP as your meds take effect. I had crushing headaches while my meds were being tinkered with (at one point I was hanging my head on the mattress on the ward in agony, while DD slept).
But White coat syndrome has real effects. You should be able to get sent away with a 24 hour monitor which will give a real reading of your BP in a non-medical environment.
Unfortunately PIH does give you a risk of chronic hypertension in later life.
Maybe it's worth asking for a callback with your GP to discuss your risks - mine were very happy to see me and want me to pop in to get my BP checked every now and again.