Is this supposed to happen to my body when bulking up?

Okay so I am a very lean guy, I weigh 132, I am five eight, 28 inch waist, seven percent body fat, but since I was casted as gaston for my ballet company's production i was asked to bulk up, so i have been doing three sets of eight, of the heaviest possible weight, i have been gorging on everything!! I have been eating thee protein shakes a day, an eight ounce chicken breast for lunch with rice, for dinner oatmeal, and for breakfast six egg white omelette sandwich, no cheese, a pound of strawberies, a banana, and a half a cup of peanut butter, that is the minimum, and i only eat healthy, very low in fat or no fat, but i have been eatinh a lot!! it's crazy, i feel like i'm getting bigger in a muscular sense, but in mhy stomach i lost my six pack, it's getting a little flab like it's a flat tummy but i lost my pack, what the hell!! i do cardio four times a week, and strength for three times. suggestions?