I always wonder how to approach topics like this. I've been where you are, at least in terms of the negative emotional cycle (not really with food), many times. I am sure I was feeling like that 10 years ago, when I was 14, too. I don't want to sound condescending, and I really don't want to depress you anymore, so I'm trying to be careful with my word choices.
Here's the thing: there's so much good information out there about eating well (primal/paleo style). I'm sure you've read a lot of it. I would encourage you to keep reading! There's absolutely nothing wrong with eating plenty, and eating good foods is only going to help you, emotionally and physically.
Stopping yourself is the hard part, but once you do it, you're golden. Maybe you have to do it a hundred more times, but every time is easier than the last as long as you persevere. Just by posting, you are admitting that you are motivated, you are just lacking that one last thing that makes you put down the bagel or whatever and have some eggs instead. It took me 10 years to get to the point where I could actually stick to my resolve for a while, and not feel bad about occasional mistakes. You are starting early and that's GREAT. Just imagine how great you could feel if you stick with this! Not just because you are sticking with it instead of "giving up" or feeling downtrodden, but because a healthy body and mind go hand in hand.
I can't give you the magic answer. No one can be your knight in shining armor to make you do anything or pick you up. It has to come from you. I don't think this is a bad thing though. How AMAZING is it that you can do it all on your own? Be proud of that.
Anyway. Hope that's a bit helpful. I wish you the best.