Nipple sensitivity

This go around I'm having to exclusively pump due to my little one having issues with latching. My nipples are so sore. She's almost 4 weeks so I thought by now it would've been better. I've tried everything to help with the soreness and sensitivity. I've used lanolin, allowed breast milk to dry on my nipples, my flanges are the right size and I don't use excessive suction on the pump. Anyone have any other ideas on something I can try. They hurt so bad even if something just brushes against them.