High blood pressure during first trimester?

I been having hypertension throughout my first trimester ranging 135/68 - 155/72 it rises when i'm walking around and being active but when i sit and rest it drops. I'm now 12 weeks 5 days and have an appointment to talk to my doctor about getting medication that's safe to use during pregnancy but is the damage already done? I've read that high blood pressure decreases oxygen to the fetus and causes brain damage and i'm very worried.. has anyone had a normal healthy child after going through almost their entire first trimester with uncontrolled hypertension?