Anyone dealt with reflux like symptoms due to overactive letdown or oversupply?

I never in my wildest dreams thought that I would deal with oversupply (as I had to be on supplements and such to keep pumping with DS1 after I returned to work). But I think I have an overactive letdown and supply. I've switched down to feeding DS2 from just one side per feeding (he was taking both but then puking up later) and it's helped a bit. But at nighttime he is still congested, wheezing, etc. after his first MOTN feed. he'll fall asleep but then an hour or so later, he starts grunting/wheezing really heavily, pukes/spits up, and then hiccups start that wake him up and keep him up until I'm able to settle him again.

I've been nursing him upright, burping, etc. so during the day we don't really notice any symptoms, it's mostly just at night. Just looking for advice from mamas with similar experience!