Welcome aboard, and I hope that Primal will be a major success for you. I too, had failed on numerous weight campaigns, and have found lasting success with Primal. You identify "primal living" in your opening, and that is important to keep in mind, the program is far more than just a diet program.
A couple of observations, if I may:
I think that exercise will be the key for you. At 5'6” and 459 lbs, I can see why you have trouble with walks/sit ups etc. To start with, I'd try and find a low-impact routine that you can do to begin building strength/stamina. I have an Air-Dyne exercise bike and think this type of device would be a good solution for you. It allows you to work both arms and legs and can easily scale your workouts up and down in intensity. Something along that line would be a good way for you to start if you can get access to one. I'm a huge fan of walking, so would also encourage you to try and work up your ability to walk. Starting slow and easy is the key, and work up gradually as you say about the exercise bands. Don't sweat it if you can't do much to start with, you'll find that getting going with a very gradual build up program will show good results over a period of time. I like your 20 minute work break schedule, very similar to what I do, I go for 22 minutes with automatic restart, and take the 2 minutes to do some light exercise and walking. Have you entertained a standing desk for your working? Here is a link to my super cheap, easy to set up/knock down “desk” idea that you could experiment with to see if a standing desk will work for you. http://www.marksdailyapple.com/forum...ml#post1487307
Are you currently doing the 50 carbs and 2K calories, or is that an objective? At your weight, these numbers would seem to me to be very low as your starting point. I would suggest to you that getting your carbs up towards Marks upper end of the carb curve for weight loss would be a good idea to start with, you may have some problems with going as low as 50. I also think that trying to hit a calorie count is not a good approach. I would encourage you to stick to the basic Primal plan of what foods to eat, then eat when you are hungry, and stop when you are no longer hungry (not when full). Try to avoid eating just because it is "breakfast/lunch/dinner" time. Let your body self-regulate your food intake. By doing this, you'll find that your carb intake and calorie intake will both moderate. I think if you take this approach you will find that you will feel better and the weight will come off pretty steadily, with some surges down, and plateaus along the way. I, too, find the grass fed option for meat to be a problem, just get the best quality you can afford and avoid the "boxed carb" foods at the store.
Lastly, give it time. You have spent many years getting to where you are, it will take time to see big results, but hopefully you will quickly feel better, find your clothes fitting more loosely and begin to see some weight fall off. Try weighing only once per week, and use your tape measure to check waist etc. once a month.
The Buck stops here. I am responsible for my past and my future. So for today: I choose to be happy. I will seek wisdom. I will be a servant to others. I will greet this day with a forgiving spirit.