Ah, Medway, I remember that feeling after DC4. It was so hard to part with things. However, what I'd suggest is this: selling will only prolong the agony, because you have to price up things you love and then risk people not seeing the same value as you etc. Is there a local refuge / maternity hospital / baby charity that might take them directly? Our health visitors round here collect good quality children's clothes up to age 12 for families who can't otherwise clothe their children (sadly, it is all too common, despite living in the Effluent South, as my DDad used to call it). That way it makes sure beautiful things are still used, but you don't have to watch them go, IYSWIM.
The other parameters I've used in the past is "could I afford to replace it if I needed to"? and "could I keep one thing as a totem", so you value your identity as a Mum (which is hugely difficult to let go of as the children grow, I know) whilest not keeping everything you've ever bought.
Keiki well done on the wardrobe but, mouldy pants? Urgh. Good job you got them out! Welcome Susie. SayitBeit that's a brilliant attitude, keep going!
I have decluttered lots of dust and muck from DS2's room. I started a Spring Clean yesterday by properly stripping the bed and washing mattress and pillow protectors etc. Last night, I basically sat in his bedroom with him until the clean clothes went away, the dirty clothes went into the basket and the rubbish went into the bin. This morning I have cleaned the windows, wiped the windowsills, dusted the lego (needs a paintbrush - terribly time consuming!), cleaned the light fitting (it's a ceiling fan as well, so needs a really good dust in a pillow case) and done a really proper hoover. I can now be reasonably certain the room won't moulder before the warmer weather arrives! Although I do still need to scrub the spray mount off the window (I blame GCSE art).
No actual out things, but plenty of moving things around and creating new systems to keep things safe / tidy. My new Monday Bills File (that I only deal with on Mondays!) is doing really well at keeping all the paperwork together and not at the back of my head at all times.