Be careful about the thirstiness, if you find yourself thirsty no matter how much you drink, and it lasts for days or weeks, then consider going to a doctor. For me, it was one of many indicators that I was diabetic and didn't know it. I'm not trying to throw a scare in you, but if it is really strange like that, consider checking with a doctor.
Does the Pizza place have a salad bar?
If so, consider getting it, just so you can eat as much as you want THERE, instead of from the pizza. If not, find out if they have any kind of veggie snacks, and get them instead. Or request tomato and bell peppers for your pizza, and get them on the side; you can munch on them after you get a slice or two in you.
There's a lot of tricks to learn, and you'll need to figure out which ones work for you, but it's great to see you making an effort.
See you around!
