Plugged ducts could be set off by trauma, or by ill-fitting bras. If you have lost 50 pounds, congratulations, but I'll bet your bras do not fit properly. I would go get refit by a very good fitter.
Plugged ducts can drop your supply where the plug is for a week or more, but just keep nursing and pumping, and the supply will come back.
I have been known to take a sterile hypodermic needle to my "milk blisters." It hurt surprisingly less than I thought it would, and it helped a lot. I'd ask my doctor for a few, using the smallest gauge possible.
Plugged ducts can drop your supply where the plug is for a week or more, but just keep nursing and pumping, and the supply will come back.
I have been known to take a sterile hypodermic needle to my "milk blisters." It hurt surprisingly less than I thought it would, and it helped a lot. I'd ask my doctor for a few, using the smallest gauge possible.