Grrlracer, I do wish all the best for you and your husband.
My father had a triple bypass last year. To be very honest, the road to recovery isn't easy. It's odd. Beforehand, with blocked arteries, he felt ok. A bit easily fatigued, but not debilitating. Afterward, with his bloodflow restored, he was very weak for a long time. He had to go through consistent physical therapy to re-strengthen the muscles in his heart and to get his endurance back up. Just be patient. It will take some time for him to get back on his feet and back to a more normal level of activity.
But in the end, after you have gone through all that, he will be much better off. After a year of rehab, my dad (who just turned 70) just doesn't stop for anything. He is out on the golf course 3 times a week. And he's constantly working around the house. It seems he always has some project brewing in his woodshop or the garage. He's building a new computer desk (from scratch) for my stepmom. And he's always fixing lawnmowers or snowthrowers or whatever other stuff the neighbors bring around. For as much as it's a scary notion right now, at this stage I have more confidence and security in my dad's health than 5 years ago.