Breastfeeding probs

Did anyone use or take anything to get there supply up... my supply is low and my baby only likes to be on my breasts &I; I would ask my pediatrician but I live in a small town known for having shitty drs and they really aren't much help they just tell me to supplement. But I'll give him a 2 oz bottle and helll never be satisfied but if I give him 3 he'll throw up from being over fed and 4 oz same thing. Once he touches the boob he's so satisfied but not gaining any weight with just the boob milk. Please help me...