I found to get rid of the lumps, massage in the shower under hot water. That worked for me and the comfort was great too.

As far as what you "should" be doing, I tried desperately to follow the nurse's instructions, but it just didn't work for me. DD would stop feeding if I took her off and wouldn't go to the next, meaning she was hungry again after two hours. Once I started to leave her alone, we'd go over four hours between feeds because she got her fill. I'd just write myself a note as to which side I used, and made sure I used the other side on the next feed. My milk supply adjusted to that. Good luck, there is no right or wrong here in my opinion. You are certainly not stupid!