Are you 'doing it' right? First time around, my nipples were a war zone, but my 'lactation consultant' (yes, I know!) helped sort that via DS1 and I- getting a proper latch. And to take him off and re-do if the latch wasn't right (my little finger inserted into the corner of his mouth to break the vacuum). Initially several times per feed. Time after time. Til we both got it right.
Basically, he was sucking on my nipple, plus a bit of aereola. I learned he needed at least a quarter of my boob in his mouth to feed efficiently. It's like (sorry) squeezing a zit. You have to get behind it. His suck needs to happen up above and behind my nipple.
It was a learned technique. I'd take him off, his mouth would go searching but I'd grab my moment, his mouth wide, to slap my boob into his mouth, underside of my boob (held by me) 1/3 onto his bottom lip and pull him towards me in an 'up and over' motion, so his top lip hit my upper boob half way up, sort of swinging him in, 'hinging' on his lower lip position, effectively slapping him onto me, and then his automatic suck reflex drew my nipple deep into his mouth.
Also, once latched, I expected, and got, a sharp pain, momentarily, with - I think the term was 'let down'. The moment the stimulation of the baby's suck 'let down' my milk. A very short, sharpish pain in my breasts, moments after a good latch was established. That's a good thing.
I remain grateful that I was encouraged to persevere. Tho no one who doesn't is a failure! It can be bloody hard! Especially without expensive personal support. And social issues come into play, I know that. And formula can transform everything if it's all going wrong.
For the record, DS2 knew, at birth, immediately how to latch. Bang.
They're 18/20, now!