Welcome to 3FC, yadummmy!
I hear you on the stomach. I had a laparotomy almost 3 months ago, and I'm getting quite irritated with my belly! Still hoping that some of it is internal swelling that will eventually go down.
I think your plan sounds great. Tracking my food intake helped me immensely, and by sticking religiously to my calorie range and exercising regularly the weight has come off faster than I expected. It truly is do-able, and if you commit yourself you can certainly make it happen.
I think getting in two walks each day is an excellent idea, and I don't think the rate at which you walk is poor at all! 3 mph was a real struggle for me when I first began. The more you do over time the faster your body will be able to move, but really, just getting into the habit of getting out and getting moving is by far the most important thing when it comes to exercise; it will help your weight loss and will definitely benefit your overall health. I wasn't an exerciser AT ALL when I began this journey, but I've turned into someone who loves it and craves it. I'm still a walker, and I do strength training 2-3 times per week as well. The benefits of the exercise go well beyond the physical; it's such a mood-booster, especially at the end of the day. When I'm feeling down or stressed or in a bad mood, my husband tells me to go to the gym - he knows I always come home happier.
Best of luck to you on your journey!