I have the opposite issue... I have severely low bloop pressure. I used to check it constantly wondering if soon I would pass out... even though I never have.
The best things I could suggest is CBT and also just realize that if it's high normally, stressing over it is what WILL make it worse. Our anxiety feeds the fire, so to speak. So don't feed the fire. Look for natural ways to lower your blood pressure and allow yourself maybe 2 times a day to check it.
I hope you start feeling better asap!