Heavy letdown - advice?

L

So this is my second time breastfeeding and for whatever reason this time around my letdown is super heavy (also dealing with an oversupply). I never had this issue with my previous baby. My son chokes and pops on and off (and the both of us get drenched 🥴) and has a miserable time and I'm worried he's going to have an aversion to nursing. He also is really gassy because of all he air I'm sure he's taking in. I've tried nursing in a leaned back position and he still chokes. Any other advice? Should I just express the first bit and then latch him?

Also on a side note, is it normal for letdown to be a bit painful? I get this almost burning sensation when letdown happens, both on the breast he's nursing as well as the other. It only lasts a few seconds and then goes away but I never had this with my daughter 🤷‍♀️