OMG Please help I have high blood pressure?

I was coming from work, and somehow I am really nervous, and my heart starts beating a little faster than usual, I am 18 years old 5'11 190 pounds, So I go to the market and measure my blood pressure and I had 150/70, I am really nervous so I think that's why my heart started increasing so fast, now I feel more relaxed. When you're nervous does your blood pressure increase? I am really anxious and stressed. Any relaxation methods, or is it lack of exercise? thank you, also what foods cause High Blood pressure, because maybe I am eating wrong. Please help