Anyone here dealing with overactive letdown ?

I have been trying to breast feed my baby , but he latches only for few minutes, gulps , sputters . Cries , struggles at my breast makes sounds like he is drowning , pushes the nipple away which is very hard to watch . Then constantly feeds again as he comes of the latch frequently- so I end up feeding him for an hour each session. I have been to the lactation consultant who has ruled out a tongue tie but wasn’t very helpful otherwise . She said that I have an overactive let down and suggested I watch videos on laid back nursing and said “ I should just figure this out and she would feed for hours as well “ . I tried pumping to see how much I’m expressing which is on average 100 ml each breast . I stopped using breast pump as much cause I don’t want to make the oversupply worse . I don’t seem to have a solution to this .