Can't control my eating, It's bringing me down, help??

I am a school girl with a keen interest in health and fitness, mainly because I have always been concerned with my own, always trying to lose weight etc. During the week, while I am at school, I can easily control my eating, I also attend the gym regularly. When I'm in public, I usually always eat healthier than my friends (who are all super skinny) and I feel happy and in control with my consumption.
On weekends, however, I rarely have social plans because I live quite far away from my friends and there isn't a lot to do where I live. This means that I usually sit in my house and don't do a lot other than maybe walk the dogs and do some study. When my parents are out, I go into the kitchen and prepare myself a fairly normal meal but then I find myself going back and looking through cupboards and as soon as I know that there's junk/unhealthy nice food in the house I feel a strong urge to eat it all at once so that I "get it out of the way". An example of this would be, I had an omelette for breakfast went back and ate some nutella out the jar, then nutella on toast, then a chocolate bar, then some biscuits, then some cereal and this is probably in the space of an hour. Once I taste something, I feel the need to keep eating and eating, it's as though my head is clouded and I can't think about my actions clearly and I feel so ashamed I also have a theory that when I've eaten one unhealthy thing, that there's no point in trying to be healthy so I go all out and keep eating. When I finally stop eating, I start to feel an incredible amount of guilt and start researching diets so that I can undo all the weight I have been gaining and I often have to resist the urge to purge all the food back up.
This isn't an issue I could ever speak to anyone about as I feel that my parents have enough worries and don't think they would quite understand the problem as I think they are quite uneducated on the subject. But it's bringing me down and completely lowering my self esteem. Can someone give me advice, I hate feeling that I'm out of control of my food intake, I just want to be normal and not think about food all the time. I'm not overweight, I'm in the healthy range of bmi for my age but I feel that that's only because I try so hard to be careful about my diet, I think if I just ate what I wanted that I would be a lot bigger.

Some more facts about my eating habits:
I Always have to finish what's on my plate
I Have always been able to consume a large amount
I like almost all foods
I am quite secretive when I am consuming junk, as I feel embarrassed at the amount I can eat (it disgusts me)

Hey girl, sorry for the late reply...i don't have any answers but you are in the right place. Is there any way you could see a nutritionist? i am also thinking, maybe being more active may help. It sounds like you are replacing social interactions with food (still comfort, to alleviate boredom) and things escalated.

Walking the dogs is good exercise...maybe find some hobbies that are available to you even if there is not much to do? maybe try to connect with more people at school?

Hope you feel better since you posted this!