I was very sore for about the first 2mo..then after that it was completely better. It wasn't horrible the entire 2mo but it was something that came and went it seemed. I was cracked, it got to the point of me crying when I knew it was almost time for him to eat again. BUT it does get better, it's so worth it once you get past that. But it is normal. I agree Lansinoh is great, though it didn't make it completely stop it did help.
As for feeling heavy I only did until my supply regulated fully...I guess it lasted maybe a couple months and then after that I no longer got engorged or anything and only ever felt really full in the mornings and even awhile after that I didn't even feel that. Only let down when he ate, but never felt really full...so for me it went away.