Wanting to give up

My daughter is 6 months old now and my goal was a year for breastfeeding. But for the last 2 weeks it has been such a struggle in every aspect.

She's so squirmy, she'll kick and flail, and wiggle around. I can handle that, it's annoying but the struggle comes from the recent pain she's putting me in. She will stay latched on but only to the end of my nipple and pull her head back, and gums/"bites" my nipple. Hard. It's reduced me to tears almost every day for the last two weeks. I don't know what to do anymore.