Hi Steve - sorry to hear of your misfortune, I had similar but not so serious (mitral valve) five years ago, got a titanium one in there now, turned my almost no existent gushy pulse into a real thump now, although downside is people are often seen looking around to find where the ticking is coming from ( i sit with a silent smirk ), did not need any bypass bit's though.
It's understandable to get a bit down after what you've been through, but I'd give it a bit of time before making any decisions, five years down the line I'm fine the cardiac rehab helped at lot ( have you been offered it) I continue to go to it although it's been split into two lots now with those of us who got a bit healthier doing the second slightly more physical session once a week.
I have two As a mild mannered Flash and a more in your face blinged up raucous rocket type hybrid, lost a lot of sweat trying to get that one to behave, now it's fitted with Pazon electronics it's a first time little prod to start it.
So give it a bit of time and thought Steve, there's not one member of this forum knows whats around the corner, you've been lucky to have had that diagnosed and acted on, think on to what could have happened if you hadn't.
All the best - Bill