I hear your concern. I am 65 almost 66. I had the band surgery on May 29. So far I have lost 40 pounds - 31 since the surgery. My highest weight wa 349 so I would optimally like to lose 200 pounds but that becomes overhwleming when I think about it. So I am opting for a little each time I weigh myself.
I also had to have the nuclear stress test - I have wrecked knees and can't do the treadmill. It was very simple and uneventful. Nothing painful - a couple of injections and a scan. Hope it works well for you.
I couldn's encourage this surgery enough. I have tried every weight loss program available - my last was weight watchers early this year. The whole thing became so overwhelming for me. My PCP suggested this and I jumped right on it. Best thing I have ever done for myself. Not one regret. Good luck