Other than age (I'm a few years older) your situation is just like mine. Started this "lifestyle" change on 6/27 and started C25K this week. First goal is 20 pounds lost by 10/1. I started at 305. Good Luck to all of you.
I'm in the same situation. 305 lbs when I started this journey on 6/27. I can do 4/5 of the 60 second jogging portions. I do feel it in my shins and my legs burn. My suggestion like most have said is to do what you can. All the matters is that you move 5/6 times a week. And of course make good food choices.