I am so glad for you that you have been trying to recover. This is the first step to leading a normal life again.
Usually after self- starvation,(1000 calories or below) once you start eating normally, you will gain weight very quickly. But after your body gets used to three health meals a day, and you exercise moderately, your body will not gain continously. Recovered anorexics aren't fat at all!
But remember, everyone is different- everyone's metabolism is different. So I would suggest you ask your doctor. 1500 calories may be a good start, but your dr, may say you need more to recover quicker. You are only 14, your body is in growing still and this is the time it grows the most. Normally a teenager should have 2000- 2500 cals a day. But since you are recovering your Dr. Will tell you how much your body needs.
Please see a Dr. They can really help you out now. I hope I have helped you a little. Take care, and keep me posted on how you're doing.