nipple shield? ftm. please help!

My little girl is 3 days old and my nips are killings me!!! They are cracked and blistered and we can't seem to establish a good latch. I don't want to give up but this is so hard and painful. She has a very tiny mouth so I feel like I can't get my nipple all the way in while feeding so her latch is shallow. Would a nipple shield help with her shallow latch? How to fix a shallow latch? Im desperate!