Is there really a way to stop a chewing addiction?

Im a 13year old teen and I`ve got adhd REALLY bad but, i`m not sure f thats whats causing it. In most cases i`m chewing gum(3packs a day) but, when i either can`t find gum o my teacher makes me spit it out; i feel the need to chew somthing else. Like the clip on a pen o a rubber band. Sometimes i skip lunch for gum and feel totaly satified. I even fall asleep with gum in my mouth half the time?
Please seriouse risposte only,
thanks for your help,
ajcisme