Blessed I am bf my second baby (he is now 4 days old and my milk has just come in. very engorged).
I am also having a hard time. his latch is toe curling, my nipples are cracked and bleeding and he is cluster feeding (every 20-30 minutes throughout the night, so ni chance for the nips to recover). It's like I'm feeding a piranha.
However, he is my second baby and I remember these times with my first who I bf for a year. he never had a drop of formula.
so i know it DOES GET BETTER. believe me. like you, I have nipples like cocktail sausages and his tiny newborn mouth cant get in enough breast to get the nipple safely back to the soft palate, so it gets clamped and chomped by the hard palate. the classic lipstick shape nipple when he unlatches.
as baby's mouth gets bigger he'll be able to latch quickly and painlessly, but it takes time.
this time my baby's latch is better because I make sure he opens his mouth really wide before I put in the nipple, but it still had me wincing each time.
It smarts but this time I know it won't be six months of this. Just a few weeks. bf really is ultra convenient, so worth this grit your teeth stage.
definitely get checked for tongue tie and have an expert watch you latch. They should be able to give you tips.
I never got on with nipple shields but they might work for you.
careful about pumping to let off pressure when engorged. Only pump off a little because you don't want to signal to your breast to make more milk. Don't let the boobs think you have twins!