Try this first- a dab of breast milk. Hand express a little bit, and dab it on your nips. No, I'm not kidding, but it does do wonders to my nips. This is why it's referred to as "liquid gold" or in my household "magic milk" (it also clears up baby acne)
If that doesn't work, consider making (or getting) Dr. Newman's all purpose nipple ointment. http://www.kellymom.com/newman/03b-treatments_sore_nipples_breasts.html
I swear by this stuff, just ordered some for my baby due in June this week!
It's called Natural Nipple Butter and works 10x better than Lansinol!
http://www.earthmamaangelbaby.com/products/product_pages/breastfeeding/Natural Nipple Butter.php?