Dear hopingtodonate,
Sorry to hear about the setback. At one point, the medical director of my center threatened to disqualify me for too much protein in the urine, which she feared suggested unacceptable risk. That was definitely one of the very worst days of my life--I felt that I was basically murdering my recipient. I'm not saying that was logical, but that's what I felt.
Anyway, I didn't give up. I remember pounding the table and yelling at the doc that I'd never had any bad kidney readings my whole life, and I refused to believe that there was anything wrong with me. She kept telling me that, while it was a beautiful thing to donate, she couldn't let me hurt myself. As I was yelling at her, I told myself how lucky I was that she "had my back", and would not lunge to grab my kidney even if it was too dangerous. To this day, I still have a very soft spot in my heart for that doc. Still, I "knew" I was really OK. We came to a compromise: if I could give her three perfect 24-hour urine collection tests, she'd allow me to continue. And so it was.
I also had had to bring my weight down a BMI point or two to get it below 30 (I remember that the last kilo was the hardest, but I finally did it the week before the surgery), and that my BP was near borderline.
Actually, that's kind of how I got into trouble with my protein levels. To keep my BP below the borderline level, I has recently stepped up my exercise, and around then I was eating lots of tofu sandwiches. Either of these can increase protein levels in the urine.
However, someone with genuine BP or other problems could really be taking too large a risk in donating, so the centers must be careful, and save overly-idealistic donors from themselves. It's part of their jobs.
I am so grateful that, in the end, I was able to donate. But somebody who cannot donate can definitely find lots of other ways to channel their idealism.
Good luck! Snoopy