You definitely need a new Doctor. My Aneurysm was at 5.2cm, local thoracic surgeons both said I can wait. My cardiologist was the same based on the surgeon's interpretation. I went to Mayo for a 3rd opinion and the Surgeon there told me that the position of the aneurysm was the determining factor because it was close to a coronary artery. if it grew anymore, it could cause a heart attack.
I decided to have the surgery, it was done 3/21/24. I am doing great!! He found that the aneurysm was larger than previously determined. I too worked out vigorously prior, and always felt out of breath. I was a walking time bomb.
His words were that you did the right thing to have elective surgery rather than wait and have something catastrophic happen. Get another opinion and a new cardiologist