My Problem Came On Suddenly The Other Morning. I Woke

My problem came on suddenly the other morning. I woke up and felt a little anxious. I took my BP and it was 200/111. Once I sat up for a few minutes it dropped to 155/88. Since that episode, I have been tracking my BP. When I lay down in bed, within a half hour my BP goes from 145/88 to 188/107. same thing each time. I have headaches and my left side and back ache some. I also have a bit of nausea.

What is happening?