I was thinking more about your situation (how you lost 70lbs then stopped losing weight) and it sound like you've hit a plateau in your weight loss. I know this sounds like I'm stating the obvious, but I mean that your body has adapted to the type/intensity of exercise that you're doing, and to get out of the plateau and lose more weight you have to try more intense or just different methods of exercise (like switch walking for running, or aerobics). In my personal experience, it has worked. Just a thought.
Hang in there, I know how frustrating weight loss can be -- as of late, my scale seems to be stuck, even though I've been working hard all summer. But then I've been doing the same work-out on the eliptical machine, so go figure. I think I'll probably lose weight in the fall when school starts and I'll be walking to all of my classes, which is what happened last year.
Good luck,
Jessie