I know it's useless for me to tell you how commonplace heart surgery is these days, and to not be overly stressed out even if your cardiac surgeon recommends a valve replacement.
But at least I've got experience to back up these comforting platitudes. I've had a few procedures myself, and been through a couple of heart attacks and a stroke. Got a pacemaker/defibrillator ticking away in my chest, and enough hardware in my cardiac arteries to build a stopwatch. I've had two different cardiac surgeons botch what should have been simple procedures (oops, maybe I should have left that part out LOL) and I'm still kickin'.
You will endure, bud...Hang in there!