1 month ago i lifted very heavy weight in the gym 120 kg later that night i felt blood flow in my head i checked blood pressure 150/100 since then i get sudden rise in blood pressure am i hypertensive or this will go away?

Unlikely that gym event has anything to do with your blood pressure, as it is more likely that you need medical attention to see if you are truly hypertensive and why. For time being, completely avoid heavy lifting, straining, and Valsalva-like maneuvers, as these could further elevate blood pressure. See your doctor and discuss how to manage this.