Really need help with panic attacks!

I'm 18 years old andI've been experiencing panic attacks for almost 3 years now. I get nauseous, sweaty, shaky, dizzy, lightheaded, my heart races, and I can't breathe. I've also fainted twice from them and threw up once.These happen out of nowhere at home, work, school, etc. with nothing triggering them. I've been to a counselor for these before and they gave me breathing techniques, but they don't seem to help. Does anyone have any advice on how to overcome the panic attacks? They aren't enjoyable at all and my parents won't let me go on medicine. Thanks!