I think I might have an eating disorder

Hi, my name is Luna. Im a teen and Ive always had a little bit of a problem with my body. On 2015, before I got into puberty I was a little bit on the heavier side, but just because I still hadnt matured. Then last year I lost a lot of weight without really trying, we are talking about [weight edited by 24Help1] kilos. I was super skinny, and my BMI showed I was underweight, but as much as I can remember I dont think I took much care about what I eat. Until about June this year I stayed super skinny, but then I gained a little weight. Im by no means overweight, far from it, Im skinny, have nice legs, a shapely butt and boobs, but a toned tummy, but I still feel insecure. So Ive started taking a lot of caer into what Im eating, and Ive been eating less than I think I should. For example, for breakfast I hades a green tea and 4 walnuts, then I had strawberries for lunch and eat something healthy at about 6 in the afternoon, so I didnt eat much during the day. Im taking care of what I eat, I dont eat bread, chocolate, candies, for example. The thing is Im restricting, and whenever I eat something that is more calorie dense, or even if I just eat like a normal person, I feel super guilty. My mother is kinda concerned, and I want to know is it posible that I have an ED?