DS2 has just turned 2. I had no feeding problems with him until he was about 12mo and started to get blocked ducts, white spots on nipple - always on the right side. I soldiered on, though, and they usually resolved themselves.
Last week DS2 had a blocked nose, so wasn't feeding as well as he could. Suddenly it became excruciating to feed him on the right side. My boob felt sore and lumpy and had a red mark on it. That disappeared after a bit of expressing, but the nipple stayed really sore and I couldn't feed him at all on that side. (The nipple is also swollen - twice the size of the other one.)
Because I was clearly in such agony, DS2 started refusing the right side, so I pumped as much as I could but didn't get much out. But on the odd occasion he has fed on that side, it's been sore when he latches on, and about ten minutes after I finish, I get this absolutely agonising pins and needles pain deep in my boob. It goes on for a good few hours after a feed.
It happened today and I've had to spend the last couple of hours hand expressing, but it's still so sore.
But for the last few days when he's not been feeding from it, it's felt fine 
Should I just stop feeding on that side altogether? I wouldn't mind that - I'd like to wean in the next six months anyway. But can I just stop? Or will my boob explode?
Thanks in advance for any help or advice. It's SO painful!