PLEASE help, i think ive made a mistake, or given in again!?

i gave in to my demons again , and only had one big bag of pick and mix which i had for 2 films at the start and end of the day, yep it was big, and filled with lots of fizzys and jelly sweets. I had with each film, 1 medium sized (cineworld cinemas) diet/ coke zero. During the day, i did lots of walking, and i've now calculated using gmaps online pedometer (which actually works it out so it equals less , due to not taking into consideration pace, climate or gradient) how many calories i have burnt. it said around 1200. now do, you guys think thats overtaken what i've consumed?



And on top of this would someone PLEASE WORK OUT my BMR , i am 16 , 6ft , 98 pounds and go on daily walks burning around 500calories a day-(600 some days) and today obviously ive done this.So i COUNT AS ACTIVE



please help, i am paranoid about maintaining the shape of my legs as they are, and don't want to go running, which i used to do daily (2 miles) ANYMORE.PLEASE help, i think ive made a mistake, or given in again!?
Okay first off if you're 6ft tall and weigh 98 lbs. You don't need to be worried about gaining weight. I'm 13, 5'4" and weigh 120 lbs. To me you sound anorexic if anything at all.PLEASE help, i think ive made a mistake, or given in again!?
You can calculate your own BMR (basal metabolic rate) and overall MR (metabolic rate) based on activity using the free weight loss advisor at LoseFatPronto.com. I've found it very helpful.