Can't lose weight?!

So for quite some time now,i have been using myfitnesspal I am a 16 year old girl, i am an athlete, i am 5'4" and fluctuate between 138 and 144 pounds. I do have a lot of muscle but my stomach has a lot of fat, my legs and arms are normal. I usually eat anywhere from 1200-1800 calories a day but i cannot seem to lose weight. I was wondering if this is because i usually eat 1200 calories, and sometimes i eat more. I heard 1200 is too low and when you don't eat enough calories your body holds onto them more and makes it harder to lose weight. I really get annoyed because i have not lost weight at all, but i usually eat really healthy. I lost 5 pounds when i was sick but immediatly gained it back. Lately, i have been eating more unhealthy because i am depressed about being in a slump, so i am going back to normal ASAP. It was a bad two weeks, but still the lowest i have gotten is 136, and my goal weight is 120! My stomach bothers me so much and i cannot understand why i cannot lose weight. Are there any foods i can eat that are super healthy, nutritious, low calorie, yet have a lot of protein. I usually eat a yogurt for breakfast, fruit mid mornign, a salad(sometimes with chicken) for lunch, or just snacks for lunch (like pretzels, fruit, and veggies), a fruit or veggie before practice, then whatever my mom makes for dinner. I do snack on things like bread, or pretzels, sometimes cheese, but i never eat chips, or candy. Any suggestions? Thanks