Should I use cream or ointment to soothe my nipples while i’m breastfeeding?

Yes. Try lanolin! it is natural and safe for your breast feeding baby. It works well for healing cracked nipples (and it also works well for sucking blisters on your baby's mouth as well!) some moms also like aquaphor- which is a vasoline like ointment that is safe to use as well.
Yes. Lanolin works well. You can even use your own breastmilk after completing the feed to soothe and toughen your nipples.