How do I increase my calorie intake?

For breakfast I had 3 eggs in a burrito wrap, for lunch I just had a sandwich with a small bag of lays, and for dinner I'm having spicy chicken sandwiches, all of this averages out to 1500 calories. I've been eating only 1500 calories for the past month and I'm worried about it effecting puberty (I'm a 14 year old guy) i've dropped from 127 to 113 and I want to be 130! I'm 5'6 and like I said 113, I have a super fast metabolism I guess because I don't seem to do anything but LOSE weight. Please help, this is very scary why I keep losing weight and not gaining a pound.