feeding nightmare?

My daughter was born on 4th of Jan and took to the straight away without a problem for either of us while in hospital. I was discharged yesterday and when I got home I put her to feed but she didnt latch on properly, She has bruised my quite badly and the pain was excruciating. I have had to coax her with formula in a bottle today but shes really upset by this, refuses it and is constantly snuffling after the , I feel really guilty and want to try again but Im in so much pain and am very scared now?