What Causes Dizziness Despite Having Stamlo?

My Age is 33. My weight is 87 KG and height is 5 8.5 . For some day i was in some kind of mental pressure . A week i was having Vertigo. I checked my blood pressure and it was ticked at 160//110. I visited a doctor after 3-4 days, he again measured my blood pressure and found it at 144/104. He prescribed me Stamlo 5. I am taking it from last 2-3 days. but some time I am feeling bit lightheadness. Please suggest.