Extremely painful nipples

Help!!! I’ve been pumping for 6 weeks but recently have been pumping more as I stopped breastfeeding. I use the Avent double pump. I’m wondering if the flanges are too big so I looked into getting smaller ones but they are impossible to buy. It’s to the point I cry with every pump session and can’t handle it much longer. I’ve tried lubricating the flanges before pumping but I find it hurts even more because my nipples are sucked in farther. Any suggestions?? I noticed small cracks on the sides this evening.