Hi, SWB.
Welcome aboard. Everyone has given you good, sensible advice. I'd only just toss in the following points.
First, the testing process if often fairly drawn-out, and can be stressful. It definitely was for me, partly due to the difficulty in predicting my schedule, partly because I really wanted to donate. And that stress, itself, could possibly influence your blood pressure.
Second, it's great that you're exercising and losing weight. Just note that exercise can dump protein in your urine, which gets the transplant center's attention. My trying to be a good boy and exercise, to increase my chances of being approved for donating, did just that, and threw a major monkey-wrench into my process. I had to do several tests 3-5 times over. That, itself, didn't help keep my BP low. On the other hand, the happier part is that for me everything worked out OK. Based on my experience, I would point out that it's worth repeating tests if they indicate problems. Obviously, a true issue with your BP, kidneys, etc., must be take very seriously. But it's also true that weather, hydration status, and exercise can influence the tests.
Good luck!
Snoopy