Breastfeeding while pregnant

Steffi
My little boy is 19 months and has reverted to being a newborn since my bfp two weeks ago! My nipples are incredibly sore and I'm dreading feeding him. Any advice on how to stop the pain? I don't necessarily want to wean, but he's up 5/6 times a night and I'm shattered and in pain! 
He hasn't fed in the day for a good few months now, and now he's asking for it in the day again! Any advice welcome! X