I'm glad to hear you're having another season with this lovely rebuild. Deleting launching, retrieving and towing removes a lot of physical and mental stress. It gives you the core enjoyment of boating without the extra work of the on-land portion.
As you move on through the post-MI period, you might find your outlook on health will change. My wife had a serious heart attack, followed by angioplasty and stents. She was fortunate enough to make a complete recovery, to the point where we were quite surprised recently to see that 15 years have passed. Apart from the handful of daily pills, there's no trace of those events.
It's understandable that the heart event is foremost in your mind right now. I sincerely hope you'll be just as lucky as Mrs Sly, finding yourself in good health a year from now, and with only fading memories of 'the big one.' Re-evaluate then in the light of (hopefully) a year of improved health and a life that has returned mostly to normal. In the meantime, it's only right that you enjoy the fruits of your labour.