Lump breastfeeding

So I’ve been breastfeeding for 3 months I’m not sure when it appeared but when I went to feed my baby I noticed a super painful spot no redness or anything it’s feels like a hard pea but smaller and painful to touch , a couple years ago I found a lump it wasn’t round like this .it’s in the inner part of my breast I had a mammogram done a couple years ago and it was fibrocystic I’m not sure if this is from breastfeeding or what I sweat so bad and both of my armpits itch sometimes