Welcome to the HealingWell Depression forum. Don't let the label "depression" scare you. There are a lot of teens going through the same thing you are right now. So don't feel alone in this.
I know that you said that you don' thave a guidance counselor. Could you get one? How about going to the department of mental health and talking to somebody there. It really sounds like you need somebody to talk to. You said your sister got over it, but are you going to be able to? Do you think you will 'grow out of this situation? You do need some guidance. We can help you as much as we can with support.
Here are a couple of sites that might help you.
I hope that some of these can help you out. I feel really bad for you right now. I want you to be happy and you deserve that.
Moderator-Depression and fibromyalgia
fibromyalgia, Chronic fatigue, depression, allergies