Can someone help me......Deficit??

According to Turbo Fire, the definition of Calorie Deficit is "the number of calories you'd like to cut out of your current diet in order to lose weight". If you're aiming to lose one pound (3500 calories) a week, then it would average out to cutting back 500 calories every day.

Some say it's debatable wether they should eat back what they burn or not, but I personally see it as a way of refuelling your body and ensuring that it's getting the nutrients and calories it needs for repair. With the equation I use to calculate my calorie target (Resting Metabolic Rate + Daily Activity Burn + Daily Exercise - Calorie Deficit), it evidently shows me that I need to eat back what I've burned from my workout, meaning the more I work out, the more I can eat.

There are some days where I feel like you - stressed over the calories I'm eating because whatever I'm doing (ex. studying) just seem to burn right through them so fast. But the important part to keep in mind is the balance. If you go over 200-300 calories a day, So you're feeling stressed - have a bit of chocolate! It's not going to completely butcher your diet if you do it moderately. On a second note, if I noticed that I'm over my calories by say 150 or so because I ate an extra banana, an extra yogurt or two, a handful of almonds exc, it's not something I would overly stress over simply because I know it was GOOD for me.

Look up "in place of a roadmap" in these forums...not sure where it is. Really good description of calorie goals, TDEE and all that other stuff!

Here is a link to the In place of a roadmap:
http://www.myfitnesspal.com/topics/show/937709-in-place-of-a-road-map-ver-3-0
and you might find this helpful too, she explains things very well:
http://www.myfitnesspal.com/topics/show/931670-bmr-and-tdee-explained-for-those-needing-a-guide