I would be less concerned about the 20lbs and focus more on only eating 2 meals. I know when there is that much time between meals I am more likely to make poor choices. Also, your body could be feeling deprived and hang on to everything. Try eating the same amount of food, spread throughout the day. As long as you are making mostly healthy choices you should be good!
This exactly, I totally agree. My doctor told me to eat lots of little meals, and so far that has been working great for me. I tend to pack in fruits and veggies when I'm not particularly hungry just so that I'm sure to get enough of the good stuff. That way I'm less likely to gorge myself on pizza and cheese fries too!
I also keep a glass of ice water with me at all times, because I actually feel more bloated and yucky when I don't drink enough. Kind of gross, but you should be drinking enough to have clear pee.
As far as your weight gain though, it doesn't sound like anything to worry about. My doctor told me at my last appointment that the weight doesn't always go on evenly like you would think. Some weeks you might gain a bunch of weight, but the next week hardly anything with the exact same diet.