Moving on is to grow and look forward to new beginnings. It doesn't mean we discard yesterday entirely...we learn from it, save the good memories and let go of the resentments.
Feeling pain at Step 4 is okay, I hope I didn't sound like it wasn't. I cried, I uncovered "stuff" I had buried for years deep down in my emotions, and yes, there was some pain, but it was the kind of pain that brings healing, the kind of pain that once walked through will hurt no more, or at least hurt less over time. But it's all good and takes us to a better place.
I re-work my steps often, as needed in my life. I try to re-work them entirely once a year because it's funny how the whole process changes as my recovery grows and my life changes. Each time I go through them I feel like I have been at a retreat, and it keeps my soul clean.
Hugs