I'm sorry you feel so bad. I understand because I have been there before. Please don't expect people to be mind readers & know what you are going through. They may just be thinking it is something minor like just growing through a bad day or something.
You should really find at least 1 person that you can confide in that you feel would be helpful to you. Is there a counselor at school that you can talk to & let them know how you are feeling? A lot of times they have very excellent resources to help students out, especially for things like this.
Try opening yourself up to an adult. Do you have a favorite aunt or something like that who you can share with?
If none of these options are good for you, set up an appointment with your doctor to discuss your symptoms and how difficult it is for you.
Keep us posted. But you have to make the first move to reach out, okay?