Ooooh bugger! It's really important to clear that blockage. To do this you need to feed feed feed. Positioning is important, try to have baby's chin pointing to the blockage, ie. if the lump is on the outside of your breast, try the footy hold. Gently massage the lump while baby is feeding, and apply a cold pack to the area after bub has finished. Some mums find that applying heat before a feed is helpful, but the cold afterwards is most important. Until the blockage has cleared, perhaps try getting bub to feed from the affected side first each feed.

At the moment it sounds like a blocked duct, not yet progressed to mastitis, but it could develop very quickly, so keep an eye out. If you start to feel unwell it would be a good idea to consult with a Dr ASAP. Good luck.