Anxiety attacks.

Lily-Anne
I'm getting them all of time no matter what I am doing, I don't understand why and it's making me feel so ill. 
I can be listening to music and I will suddenly get the weightless feeling in my chest, accompanied with feeling lightheaded, nauseas and feeling like I am suffocating. 
It varies on severity, but it's happening more and more frequently, when I'm drawing, when I'm on the bus, at school, in toilets, walking, laying in bed, it's getting to the point where I feel as though I'm going to throw up or go mad with how awful it feels. 
What can I do?
I do breathing excercises which were helping, I've been to the doctor but due to my age they won't give me anything for it. 
Any other techniques? 
Please help, any advice appreciated.