What Causes Elevated Blood Pressure Along With Headaches?

I am 29 years old and have been having high blood pressure for a couple months. It began to get higher 160\112 was the highest. I ve been put on amlodipine besylate 2.5 mg. 3 days ago. I have been having headaches and feel like my body is on fire. Just a few times. Not all day. I have stage 3 renal failure. My bp hasn t changed since starting the meds.