Why have i not lost weight?

Hello! I am 15 years old and went on diet! I put another question up last week on how to lose weight and followed every serious answer! I weighed myself and was 191 when i started! Until this very day i have been eating healthy and running DAILY. My daily routine would be Waking up, brushing teeth, going out for a 3mile jog! then would come back! Shower, eat a meal, and from there eat a few healthy snacks like Fruits / Smoothies / Low fat yogurt / Fiber cereals and much more. I would stay at a 1,000-1,500 calorie diet! I decided to weigh myself today considering i thought i was noticing results. I checked myself and was 191.3 . At this point i feel like a failure. I dont know what i did wrong? Can anyone help! Please. I am already feeling as if all the work i did was a waste!