Heya,
Can you give your GP a ring and ask them to chase up your referral or let you know how long it might be until you hear something? There can be long waiting lists, but you should have heard something back from them by now. My GP was really helpful at getting my referral through quicker when I was struggling with my ED, so it is really worth doing.
Do you think you could try to write down your feelings about your eating in a letter and leave it for your parents to read? I know it's difficult with EDs because you can get very defensive and protective about it, and it's hard to think about letting it go, but it's really important that you get support with this and it would really help if they can understand.
It's understandable that you're struggling with the eating with the stress of exams coming up too, and I can certainly relate to what you say about calories and the foods you're eating. It would really help (both for the sake of your health and to help you with your exams!) if you can try and keep things as stable as possible with your eating. If you restrict you're more likely to end up binging too because your body will be crying out for food. It would be ideal if possible to manage 3 meals and 3 snacks a day (although I know that can sound scary!), but at the very least, try to make sure you eat regularly (at least every 4 hours) and don't go for long periods of time without eating anything. Please please please do not fast to compensate for binging - like I said, it actually makes binging more likely. The best thing you can do is take it one day at a time, each day is a fresh start.