Mastitis?

Earlier today I noticed a certain spot on one of my breasts was becoming tender and pumping was uncomfortable. Throughout the day the pain has gotten worse, it hurts even to hold my daughter on that side because she touches my boob. I’ve been having her nurse that side and pumping it and it temporarily relieves the pain and the lump but it quickly comes back. It is starting to hurt under my armpit. I do not have a red spot or a fever. I’m extremely fatigued (but nanny two toddlers and have my two month old). I just don’t know if it is cause for concern or a normal breastfeeding thing. Any advice?