I have no idea why your cardiologist was so somber about your condition. It's extremely common: 1 to 2% of the population has BAV. With that kind of numbers, this is a major public health issue. But this is offset by the fact that it is essentially cured by AVR surgery with an extremely high rate of complete success. The surgery is routine for surgeons like Dr. Stahl.
I know that after 52 years, to learn you have a serious heart condition that requires surgery rather soon is a rude shock. It was for me as well. But after a little study I learned how overwhelmingly successful AVR is, and I found a surgeon in whom I had complete confidence, so I was rather at ease regarding my prospects. Within a year I got the surgery and after several months of recovery I was back to doing ANYTHING I want to do with only an occasionally itchy scar to remind me about what happened.
Edit: I just noticed the later post that noted you are having sugery tomorrow (actually today!). Man, that was fast! Congrats on getting your head wrapped around this so quickly. It took me months to do my research, but you didn't have that time. I look forward to hearing from you post-op!