My DS had similar symptoms. Fighty on the breast, crying immediately after feeding, bloating, severe discomfort, and green, frothy explosive poos that could shoot across the room. He also developed rough reddish skin on his cheeks. I had/ have a LOT of milk. I spoke to a lactaction consultant who pretty much told me that I didn't have a problem. 
My breast-feeding books suggested everything from elimination diets to nipple shields. Nothing helped much.
We battled away from 1 week to about 5 weeks at which point I visited another paediatrician who suggested lactose overload from endless short feeds of foremilk, leading to excess fermentation and gas production in the intestine - this gas obviously cannot be burped up. (I already reckoned something like this to be the case from hours of midnight googling).
She suggested simply spacing out the feeds to intervals of 3-4 hours and introducing a soother to satisfy his need for comfort suckling.
(I had being trying to block feed which just exacerbated the engorgement. I was pumping about 50 watery mls off when I was just bursting but if emptied a boob I'd get 150 to 200ml. I had even been mashing my poor breasts as advised by another eminent online source in a presumably fruitless attempt to mix foremilk and hindmilk.)
Anyway the spaced out feed routine (continuing to pump a bit when overfull) worked extraordinarily quickly and everything had normalised within 24 hours. I didn't really adhere rigidly to the schedule but DS seems to naturally want to be fed every 3 hours anyway and now that my supply has settled down, it's a relaxed pleasure.
I hope everything works out for you soon. Do try a lactation consultant or doctor. Or two.
(Obviously this is only my own experience and you may be dealing with a different issue.)