The majority of your weight loss progress will come from diet, not exercise. Are you tracking all of your food carefully and staying in your recommended calorie and nutrient ranges?
As far as exercise goes, you'll want to work with your doctor to decide on a good plan based on your medical history. In general, most people can get a good workout in 30 (or so) minutes of cardio, 3-5 times per week. You don't really need two sessions a day. If your doctor gives you the okay, I'd also recommend adding a full-body strength workout to your routine twice a week.
Hope that helps,
"You may have a fresh start any moment you choose, for this thing that we call "failure" is not the falling down but the staying down." Mary Pickford
"No matter how slow you go, you are still lapping everybody on the couch."