Looking for some guidance

epbowers

Alright, so I started doing this last year during my first year at college and I completely failed. I swear my body must have went into starvation mode and I was restricting my calories way too much and then doing very high intensity workouts everyday (I would be eating like 1200 calories and burn like 900+, it was like working out was a chore and eating was a joke). It's obvious to say that I made absolutely no progress and I felt I cheated myself and wasted time.

After gaining like 20 pounds to my roommate and I's Insomnia Cookies tirade during the spring, I decided enough was enough.

I got back to working out, but less intense and made sure I was eating adequate amounts during the summer, but then life and 70 hour work weeks happened and I got off track.

Now that I am back at school and have a really nice gym to use, I want to get rid of the weight I gained, but I want to do it right.
MFP says I should eat 1570 calories a day, (I want to go from 167 to 140ish. I am 5' 5"..I'm a female) so I guess my question is how many calories should I be burning in a workout?
I try to do 40-50ish minutes of cardio a day (I do various things, I usually warm up with a run/jog that is either a 1/2 mile or 1 mile, I do the stairmaster on the fat burner program level 8 or 9, and a couple other cardio machines, and/or bike) then I do some weight training for about 20-30 minutes (I try to rotate the days I work on certain parts of my body) overall, the cardio alone has me burning 400-500ish calories, and then there's the weight training which I don't have a number for.
Overall, I am a very active individual, besides working out everyday (sometimes I take a day off), I'm in marching band, walk or longboard around campus, always take the stairs, and have a job in a dining hall where I am always standing, cooking things, moving, etc. I have my activity level set as "lightly activity," I suppose that is close enough, but I think maybe I am more active than I give myself credit for most of the time, so I'm not sure about that.

I've also heard debate on eating back exercise calories, I'm unsure if I should or not. I really want to lose the weight, so if it will help me, I'll do it. But often times I just don't have the appetite to do so, so I'm not sure if it's right or wrong.

So basically I want to know how many calories I should aim to burn given the 1570 calories I am allotted to eat and whether or not I should eat back my exercise calories.

Sorry for all the questions/long post, this community seems to be really helpful and if I'm going to meet my goal I'm definitely going to need some help.

Thanks for reading!