Get a tube of lansinoh and some jelonet gauze from the pharmacy. Put a good dollop of lansinoh on, then cut a little of the gauze and put that over it, that will stop the nipple sticking to your bra. That might help heal up the crack before you start bfeeding.
If you still struggle afterwards, keep using the lansinoh and the jelonet between feeds. The Lansinoh is fine for baby to get in their mouth, just wipe nipple before feeding, you needn't wash it off or anything.
You might need some help from a bf counsellor to show you some different ways of holding baby whilst feeding so that it is the most comfortable/least painful on the cracked nipple.