I know @Mrs. Sketchbook: and @Mrs. Wagon: battled some oversupply and forceful supply issues with breast-feeding. Hoping they and others with similar experiences can chime in with some advice here.

I think I have an overactive or forceful letdown since quite early in breast-feeding. The milk comes out SO fast, baby is always choking and gagging the first couple of minutes! I feel SO bad! Despite the fast letdown, I DON'T think I have an oversupply. If I try to pump or hand-express, I get a pretty fast and plentiful flow for a minute or two only. If I pump, I rarely get much past the 5 min. mark. Most everything comes out before the first 2-3 minutes. She also never has the green, foamy poop.

I think recently, as my supply is regulating (I'm almost 6 weeks pp), that it's gotten faster? K has stopped sucking hard, in fact sometimes she just puts her mouth on my boob and I can see all the milk over-flowing out of her mouth. She comes off the boob, half her face is covered and dripping in milk.
If I wait too long for her to wake up or have my boob exposed before feeding, I'm often drenched wet before I can even latch her on!
I literally had to change my top 3x's last night, and often have to change K after a feeding because I've soaked her sleepers!
(Worse yet, I have to try to "air out" my nipples after feeding because of the thrush.)

During the day time, it's a lot easier to control. She nurses more often and I block-feed as much as possible.
I DO think the overactive letdown contributes to her reflux/spitting up issue and her constant hiccuping.
I already nurse her with her in an upright position, and I try to lean back so the flow has to go against gravity.
My problem really gets bad at night, when K sleeps for longer stretches. She gulps and chokes and gags always.
It's been hard to guesstimate when she'll wake up to nurse, so I can't always hand-express to help alleviate the choking/gagging. And if I try to do it once she's awake, she's crying and fully awake by the time I can latch her on.

Does anyone have any experience and advice on how to prevent her from choking & gagging every night feeding?