Painful feeding while weaning

My baby will be 1 year on September 3rd and I started to wean from breastfeeding this past Monday. Maybe around a week before I started weaning (switching out one feeding for a bottle feeding) my left nipple/breast started hurting during feedings, while she's eating my nipple would hurt almost like she's biting but she's not and I don't really have any issues when she's eating on the right breast. When she's done feeding the pain gets even worse and it goes from just the nipple to radiating from the areola to deeper within my breast like a sharp burning feeling. There's nothing I can see on the outside that's wrong and it all hurts on the inside. It hurts for about a minute or two after the feeding but it's become extremely painful and I'm at the point now that I don't want to feed on that side at all anymore since I'm trying to wean from breastfeeding anyways. I don't think I have any of the symptoms of mastitis or a clogged duct so I'm not sure what this is or why it's happening. Does anyone know what this could be? Should I just stop feeding on that side since I'm trying to stop anyways.