Just a comment -- your Atkins story mirrors mine... dropped from 270 down to 210, then over the course of two years gained it all back and now starting over.
After a lot of thought, I have decided that Atkins is not the way to go -- it is great for quickly losing a lot of weight, but it is not a lifestyle change and cannot be maintained over the long haul. Eventually, you start eating "normally" again and everything is gained back.
This time I'm eating sensible portions and working out -- deciding that I have to make time to work out was the biggest step. In any case, after 5 months I feel that I have a new, healthy lifestyle -- one that will slowly take me to my target weight, but once there the lifestyle change will allow me to stay there.
Good Luck