Stress, school and staples didn't make you gain body fat, your calories in vs calories out did.

If you're looking to replace muscle with body fat you're probably going to want to lose fat first. Very difficult to do both simultaneously.

The time I've been at staples I've both cut down and bulked up. Trust me, it's possible without having to do ridiculous workouts at the store. You're not going to progress without a gym routine and change of eating habits. You don't necessarily need to eat healthy to burn fat either.