Get a right size for flange. Stick to one. If not, nip will be painful n can’t pump well.
I had that back then while bf my lo. I kept applying Nipple cream n let it cool down for 2 days. And feed fm. But I managed to pump (lower suction) next day. Hurt a little but still ok.
Maybe you can try lower suction n pump lesser. See if it’s ok.
If u have ebm in freezer/fridge can let baby drink while let your nip rest too. If Not can consider fm for 1-2 days.