I feel for you! Breastfeeding is HARD. My girlfriend had issues getting her baby to latch and it ended up being because he was tongue tied. Have you ruled that out? I would recommend seeing a lactation consultant if you haven’t already. They are so helpful! And use silverette’s (Amazon) and Mama Earth nipple butter for sore nipples. I had to triple feed with breastfeeding, formula and pumping for a while until my supply increased. It was a nightmare but got my supply to increase pretty quick. Also try Mother’s Milk tea!
Try MAM nipple shields, absolutely saved my breast feeding journey with my baby. Also get your baby checked for a tongue tie as that might be causing the issue.