Veganism

Going vegan for health reasons is an interesting proposition. While it can be very healthy, it can also be very unhealthy, in that by limiting your food sources so significantly, you have to be way more careful to ensure you're getting your required macros and micros, whereas an omnivore with a varied diet often meets those markers by default. Have you studied up on what you will be getting from food compared to what you might need to supplement? Vitamin B12 is a big one - vegans often need to supplement that and it can be quite harmful to be deficient.

Nothing against going vegan, just wanted to point out that it isn't 'healthier' by default - it's actually a fair bit of work to make sure it balances.

Nutritionfacts.org is a site run by Dr. Michael Greger that has hundreds of 3-5 minute videos talking about the science behind veganism. He has a strong point of view about the benefits of veganism so to many he comes across as an extremist but he presents a powerful argument. I'd recommend checking it out if you are interested in going down that path. Anecdotally, I have parents who have been vegan for about 10 years - my Dad is turning 89 this year and Mom 84 and they just returned from a trip to Europe (they live in California), still sharp as a tack. Their strict diet is a big part of their health equation.

Regarding high blood pressure, diet surely plays a big role. However, there is also a hereditary aspect as well. I eat minimal junk or meat, high amount of vegetables and fruits, very little pasta or breads and am very active but I've had to be on BP meds for nearly 30 years. Same story with another athlete I know who has completed multiple Ironman events and is also a healthy eater.

I'd recommend continuing to monitor your BP and if it's consistently at or above the borderline levels talk to your doc about BP medication options. There are a lot out there considered completely safe with little or no side effect.