Can I diagnose myself gluten intolerant after finding out that I get bloated, extremely gassy?

Nah. Too many other variables. Gluten containing foods also have carbohydrates and starches, some are not well digested and can lead to bloat and gas. Sometimes it's not the crust of the pizza, it's the sauce, the oil, the cheese, the pepperoni, the spices, garlic, etc. Want a diagnosis? See a doc, get tested.