what to do to help with breast feeding pain?

Definitely make sure your baby latches properly. You might want to see a lactation consultant to make sure you're feeding your baby correctly because that is the number one cause of nipple soreness. You could also buy Lanolin ointment for your nipples (I was given this in the hospital, but you can find it online and in stores). For temporary relief, you could put warm wash clothes on your breasts. If you really need relief, you could try using a nipple shield. They really help minimize pain while feeding, but I would be careful with that because if you use it too much your baby might have a hard time nursing without it (nipple confusion).

It will get better with time. Your body is getting used to breastfeeding. And it's completely normal for you to produce more milk on one side. Just keep feeding your baby like normal and keep switching sides after 15 minutes or so. The milk production will likely even out in time.

Make sure he/she is latching correctly. Buy nipple ointment.