New advice for any blockages is ice and ibuprofen, I remember with my first it was keep feeding, and the pain definitely lasted longer on several occasions, and i had one bout of mastitis. I also got a couple when weaning off it, i ended up using my haaka once a day for about 2 weeks less and less each day to really wean it down. This time she's had a couple of bad latches (my own fault being with in laws and trying to "hide") and i ended up with couple of blockages .. I took ibuprofen for the day and stuck some peas on it when I could and it cleared in a day, so definitely better than the old advice of pump or feed to clear it!! Try ice and ibuprofen and if it gets hot and more sore go to GP straight away for antibiotics. To add even after stopping the haaka and all feeds it took 3 months for my milk to dry up with my first so I'd be cautious that it could be a blockage
It could potentially be cellulitis. I got it after stopping breastfeeding so immediately assumed mastitis. Was in SO much pain 😬
Sorry , can't speak from experience but could be that one breast used to produce more milk, could be that having your baby near is stimulating somehow or maybe breast are shrinking and it hurts .. mine looked like raisins when I stopped. No real advice as it did not happen to me. Best to ask your GP or HV. Hope it's nothing