Can you try to write down a list of what makes you anxious about being in school? Even if it just seems like little things to other people like the smell of the corridors or something, it might help you to give a picture of what it's really like for you, which they might be able to take on board? If you write it down, then you won't have to try to remember it and they won't be able to mishear you or try to put another spin on what you're saying. It's just that it might help if they knew exactly how they could change things to make it somewhere that provokes less anxiety for you, rather than them thinking its just like you can't cope with anything or everything.