Why am i not losing weight?

I have been going to the gym exercising a lot every morning after breakfast. i eat honey nut cheerios for breakfast then after gym for two hours i will come home and eat either a tuna or turkey or bologna sandwich for lunch then around 5 or 6 i will eat either a wrap or some meat for dinner. I have been doing this for 3 days and i have done nothing but gain a pound or two. what am i doing wrong?!?!?