Don't panic about this. The best thing you can do to reduce your blood pressure is reduce your weight. Even a few pounds can make a significant difference. There are loads of tips and advice free online and lots of diets you can follow, but you can do things yourself that will not require much change in your diet but will reduce your weight.
Here are a few of my tips:
Reduce portion size, use a smaller plate. Fill up on veggies and fruit.
Drink a glass of water 20 mins before a meal, it will make you feel full quicker.
Seriously reduce the amount of fat in your food, for example butter on bread, or oil in cooking. Try to use only half of what you have been using.
Don't snack between meals, if you have to, raw carrot is filling and low in calories (compared to chocolate).
Build more exercise into your day, but begin slowly. Don't pound yourself into the ground on day one!
Walking around more, even if it's gently strolling will burn up more calories than you have been burning.
Your blood pressure is not too high, and I think reducing it by losing some weight and getting a bit fitter is very achievable. Good luck and let us know how you are progressing.