I am teen with an addiction, help?

Ok I'm 13 and since I can remember Coca Cola has been in my life, it started with about two, one with a snack when I got home from primary school another with tea, and no problems really just what I had to drink, then over time my friends would come round, I'd offer them a drink and have one myself adding, and eventually it has now grew to about 8 cans/ glasses of Coca Cola, which although seems simple, just give it up, I fear the worse. I am a very fussy eater and my diet consists of ham sandwiches, bacon, sausages, toast and pepperoni pizza, literally that is basically my regular diet, I only eat once a day and that is tea, I would have a can before 1st period at school, a can at break and a can at lunch then another 5 at home before during and after my tea, and whenever I don't have those cans I feel rather drained of energy to say the least, in fact when one of my cans was stolen I began to have migraines and was unable to stay around my friends as all I could think about was my stolen can. The reason I'm seeking advice is because I just feel like I can't win, the reason I was first given coke if because my blood sugar levels used to just randomly drop and I'd get what was known to my 6 year old self, "the shakes" so the doctor informed my mother to keep a bottle of sugary drink in the fridge to give to me when this occurred and one day I was out of Sunny D and wanted that instead, I am now seeking help because puberty has recently just hit me like a ton of bricks, my acne is getting worse by the day, I already have incredibly pale, oily skin, but the acne recently popped his head around the corner and I a very focussed on my (and others) looks and some days seek refuge from not even going into school because my acne is that bad, my last resort would be a certain group of pills with horrid side effects, but giving up the Cola should help first, after all I'd rather go without coke than go bald when I turn 14. So what I want to know is what to do, if I stop the coke I will be drained of energy and will not be even able to keep my head up, I know this from experience, the only way to counteract this would be to eat during the day, but with my limited diet it seems like an unwise choice because I'm not too sure my flat stomach would remain, and eating that crap once a day is bad enough never mind 3, I'm almost certain that would make my acne worse, the ideal solution would be to eat normally and quit the coke cold turkey, but I would literally need someone restraining me from my fridge to quit coca cola cold turkey, forcing some veg onto me too would just be plain torture and I simply do not have the willpower at all, I eagerly wait a reply here as I really wish to know of a good idea, if I quit the coca cola I would have to remain off of school for a few weeks at best because my focus would not be on lessons at all, and I'm sure vomiting when I'm forced to do a sprint when I literally don't even have the energy to move a pen would be a good idea