Sorry, I wish I could offer more words of wisdom, but I'm not super familiar with your condition.
My only advice would be that you still continue to see a pediatric cardiologist at an Adult Congenital Heart Clinic.
As some one that was also born with a heart defect, I too grew up with the watch and wait. I had my first open heart surgery at 37. I am so glad I was able to make it so long, but I understand the anxiety that comes along with living with all that in your mind.
Best of luck to you!