Mosschops I am going through exactly the same thing as you (hewlettsdaughter has linked my thread below) - but about a week ahead of you (dd was born on 6th jan). It does get easier honestly. I'm not sure whether I have got the latch 100% right yet, but it definitely isn't so painful now.
Do phone the NCT help line - they will put you in touch with a local counsellor who will help. I have also seen a counsellor at the hospital who has taught me the enhanced latch - that has helped alot. I have got over the worse pain by doing the football hold instead of the normal hold - this takes the pressure off the existing crack and puts it on a different place. Also go to your doctors and get some painkillers - I have codeine - it does help. You can take this alternately with paracetamol.
I know what you're going through, a week ago I spent each night in tears, thinking that I would have to give up. Now it is still painful, but more bearable and I feel more able to persevere (although nights are still the worse time).
Finally do check whether you have thrush or mastitis. I definitely had one or both of these as there was unbearable pain after feeding which didn't seem to be related to the cracked nipples - it has now gone with the antibiotics/thrush cream (I'm not sure which one of these has worked!).