Did I ruin this for myself? Please help!

No
Around 2154
The amount you burn is up to you, but you should eat those cals back.

I'm 18 years old, 114lb 5'2 and maintain on 2300, but I'm also pretty active naturally.
I think 1700 would be good if you walked 30 minutes a day, started C25K and strength trained 3 times a week. I used to be 109 but I started lifting and went up to 114, my waist went from 28" to 26.5" even though I gained 5lb. Dat muscle.

You don't need to wait until all the excess fat is gone in order to start lifting! Lifting increases your muscle which speeds up your metabolism, meaning you'd lose the fat even quicker if you started to lift.

Your metabolism is fine. It's definitely a balancing act to keep the weight off, especially since you want to be at the lower end of a healthy weight range. Most people's bodies hold onto weight pretty naturally. As long as your previous way of dieting was healthy, just do that again and the weight should come off.

I'm sorry, but did you miss the "not eating for days" part?

Honestly, I think you'll be fine metabolism wise, but maybe you should look into some sort of nutritionist or therapeutic help.. you already know that not eating and the bingeing isn't healthy but it worked, so the temptation to do that again is there. I have first hand experience with this, witnessing someone I was very close to do this to herself. I'm not trying to be mean, I just want you to be as healthy as you can :flowerforyou:

First, relax--you haven't messed up your metabolism, and if you stress too much about "messing up" you're going to psych yourself out.

I'm 5'6" and I maintain around 1600 calories a day plus I eat back my exercise calories. There are more scientific ways to figure out what your maintenance calories are, but I'd suggest starting somewhere around 1500-1600 calories a day plus what you burn through exercise and see what happens--if you lose, great, if not, lower your calories a bit. Just don't go too low or you risk falling back into the binging trap (I've been there, and it's a vicious cycle). For exercise, I think an hour a day 6 times a week is about perfect. Do what you like and will stick with, but you'll get the best results from weight lifting and intervals.

I plugged your numbers into Scooby's calorie calculator.

This is what it gave me at moderately active:

BMR - 1385 (read - don't eat lower than this!)
TDEE - 2148 (read - eat this amount to maintain)
-10% - 1933 (this is what you eat to lose nice and slow - and you can lift at the same time! - you'll have lots of energy, lose inches.. feel great, and lose weight!!)

I plugged your numbers into Scooby's calorie calculator.

This is what it gave me at moderately active:

BMR - 1385 (read - don't eat lower than this!)
TDEE - 2148 (read - eat this amount to maintain)
-10% - 1933 (this is what you eat to lose nice and slow - and you can lift at the same time! - you'll have lots of energy, lose inches.. feel great, and lose weight!!)

And with his calc I don't eat back exercise calories right?

That's right. The calculations were done with activity level in mind (moderately active), so if you want to log your exercise, change the calorie burn to 1, as to not change any goals. Happy eating! hahaha

Now, the way I transitioned from 1300 to 1800 was I gradually added in 100 cals a day over a week, then another 100 over a week, until I got to 1800. It was scary, but not so bad when I got there! Just avoid the scale a bit as you are transitioning - if you've been eating low calories for a while, your body will scream "YAY FOOD!!" and you may gain a little.. but it will be temporary!!

I would put your activity level as high with the two jobs you have. The way I look at it is that I don't care how fast the weight is coming off, if I can lose at a higher calorie level, but maybe more slowly, I'm going to go with the higher level. Your body will adjust to whatever the amount of fuel you are giving it. If you are consistently eating too low for your activity level it will adjust to preserve energy for necessary body functions. If you enter your numbers in to a calculator as active and that number seems high enough to make you gain weight I would say that you may have done some metabolic damage. If you are maintaining at those numbers I would say you are fine.

I lost weight starting in here following MFP guidelines but I entered my activity as sedentary and that I wanted to lose 2 lbs a week. That gave me about 1600 cals a day plus eating back my exercise cals. I actually was losing weight faster than 2 lbs a week, which I now know means I estimated my daily activity too low. At the time I was thrilled and every time I lost 10 lbs MFP suggested I lower my cals. In a couple months my cals were around 1400. I started to feel tired and hungry a lot. My hair started to fall out and my weight loss slowed to almost nothing even though my workouts increased. Two months of that was enough for me. I upped my cals to back over 1600 and started to feel my energy come back. In a month I started to feel hungry a lot again and I upped my cals again to over 1700. I also started keeping better track of my protein and iron, eating a minimum of 100 grams of protein a day. My hair stopped falling out and began growing back.

It's a long story but I have continued to up my cals when I listen to what my body is telling me. Your body will tell you what it needs if you listen to it. I now eat 2000-2500 cals a day and continue to lose. I have been losing much more slowly. Maybe 1-2 lbs a month but I am losing inches. I think that is due to starting a heavy lifting program about 3 months back. I can't recommend weight lifting enough. I took my month of May pics last week and was totally stoked to see a big difference in my stomach compared to the month before even though my weight stayed the same. I'm ok with that.

Sorry this is so long. I have just become a passionate advocate for properly fueling our bodies. It makes me sad to see so many stuck in the diet cycle.