Breastmilk everywhere!!!

I think my boobs are making too much milk, she nurses good for 40 mins every 2 hours and shes gaining weight really good but i think my boobies are making too much of it and idk why. As soon as she eats i can feel my boobs fill right back up and they hurt again in like an hour and its not time for her to eat again. I dont wanna pump also cause then my body will make even more milk, omg im in pain and dont know what to do