Awesome to hear you are feeding with less pain now

Do keep expressing & trying to feed off your left side but don't worry too much about a drop in supply. It is amazing how quickly your body will adjust. Bub will get all the milk she needs from your right breast, and when you do go back to feeding on the left it will adjust again. You might want to do a few extra feeds on that side to help it along, when you're ready.

It is normal for one breast to be a super milk producer - mine was my right

As for blocked ducts, as Peanutter said suggestion of massage in the shower is great. Keep expressing on that side & be aware of any tender spots that develop.

Good luck!