Hi
@mazhot and welcome to the forum.
Prediabetes (in the UK) means that the result of an HbA1C test showed a result of between 42 and 47. Diabetes is diagnosed by 2 HbA1C results of 48 or over, and many don't get diagnosed until it is much over 48 and into triple figures!
So you may only need a few adjustments to what you eat, in order to get you back into the non-diabetic range.
Even people who are Type diabetic are often able to put that into remission despite starting with an HbA1C of over 100, so the odds are on your side.
Diabetes (both Type 1 and Type 2) is an inability to handle the amount of carbohydrates in the modern diet (but for different reasons - unfortunately there is no remission from Type 1).
The 2 most common paths to remission from Type 2 (both of which should help reduce high blood pressure ) are:
1. Substantial weight loss through a crash diet of approx 800 calories per day, for 12 weeks. There are several different variation of this of which Newcastle Diet and the FAST 800 are best known. There are 3 hurdles with these A). Not all Type 2 diabetics are overweight, so may feel they can't afford to lose so much weight, B). Sticking to it isn't easy, C). Adjusting to a new way of eating which maintains the new lower weight.
2. Since the problem is carbohydrates, adopting a Low Carbohydrate Way of Eating (no conscious calorie restriction) is a good/better alternative. The only hurdle is sticking to it.