Hi, I Am 16 Years Old, And For Almost 8

Hi, i am 16 years old, and for almost 8 months now, im constantly spitting. If i don't eat anything ill spit more than usual, or if i have a bad breath for example when i wake up, i spit even more. I am tired of this and have no idea either what is it or how to stop it, its really embarrassing for me when i have to spit and there are people around, please help me please.