Hi K.,
I breast fed my son for 11 months and my little girl is now 2 months and she is still breast feeding. I understand how dfficult it could be for the both of you.
My advice, try relaxing yourself first, remember that if your tense she will feel it. Find a quiet place in the house where there will be no interuptions of any kind. Also attempt different positions, like the football hold, this is where you place her underneath your arm as though you are holding a football, with her legs tucked underneath you(towards your back). This helps her latch on at a different angle. Also when you begin to feel her bite down and pull away( trust me I know this hurts!!) insert your finger on the side of her inner cheek and pull out words this way you release the preasure and she can latch off of you pain free.
If you can try finding the best time for her to feed, like as soon as she is up from a nap or so when she is calm(not when she is crying so hard she is frusterated herself.)if at all possible try and sing to her and talk with her before feeding to let time go by and she is hungry but not upset. Help her by using your index and pointer finger on your nipple and squeezing it between the two, then insert it into her mouth this helps her out a bit as well.
I wish you the best of luck and remember dont beat yourself up about not getting it the first few times its normal and okay, keep trying and dont give up. In the end if you see that she is still not eating enough its okay to pump and do formula she is still getting all the vitamins she needs and you are still bonding with her by holding her close and talking to her. Remember that what is important is that she eats and you enjoy eachother, you cant have a healthy baby if your both stressed out during supper time. :) Good luck hon!