What Causes High BP Along With Pain And Stiffness Of Muscles?

I get these attacks that start out like a shot of adrenaline. My stomach tightens and I shake,m sort of like an anxiety attack but not. My BP goes to 200/100. Under my skin burns like fire. It lasts about 1 hour then peaks with every muscle tightening in horrible pain for 5-10 minutes. The pain so bad I scream. Then it stops and goes away. It happens 2-3 times a day. I ve been told it s my kidneys, Seretonin Syndrome, and anxiety. No one makes up their mind. I am miserable!