Why is nipple so sore with clogged duct?

Neska

So I had a clogged duct yesterday that I rubbed the crap out of in the shower, had my baby feed off that breast, pumped etc. I think it’s mostly gone, I don’t feel a lump anymore, but my nipple is very tender and sore. I don’t have a bleb in it, not that I see. It kinda hurts when she latches. This is my first clog so I’m not sure is this normal? Maybe caused by all the downward flow I was doing towards the nipple, I’m not sure.