Best diet to get in shape?

i use to go to the gym almost everyday & started eating healthy, & i absolutely loved it. i felt awesome & looked great. but lately i've been stressed & studying for my real estate exam this friday, so i haven't been to the gym in over a month & have gained a few pounds and i hate it. i recently moved into my apartment, so i want to find a good diet that will help me lose a few pounds, help me feel healthy & energized everyday, tone up, & still not cost an arm & a leg since i'm on a budget. i would love any breakfast, lunch, & snack foods that anyone thinks would help me & any recipes for dinner that i can throw together in a pan, crock pot, or the oven. please help me, i want my old body back!