I am so sorry...this is so tough. I remember moving out (in like 24 hours) - it was unreal.
We're in the same boat...I recently got all my things from storage and am now going through each box. Lots of letters, pictures and memories. Hard to really read and look at now....seems so unreal. It's not as sad, b/c it's like looking at another person that I thought I once knew.
For me, what was easier was not to face all the details at the moment. I just took what I could initially (1 year ago) and recently, I took all the things that were mine. If H's stuff is mingled, I will give it back to him later, when I am able to go through the things in a more stable state (and when he's not such a lunatic, but I may be waiting forever for that one! Let's not hold our breath!).
Sometimes, in addition to feeling like we are the cause of the demise of the M and the feelings of failure, we take it on to save the M, and now that transfers to being the one to do the separation and move. Our spouses have cleanly placed us in a position of picking up the pieces for EVERYTHING. The M, the move, the saving the M....and we become so used to it.
But, there aer ways we can pull ourselves out of that.
If this is too much, and too frustrating...can you call H and talk to him (I know...a miracle in itself) and ask him to work with you on making this easier? Can he come on a weekend when you are not there and pack up things he wants? Work with S14 while you are out taking a break?
Seriously think of these options, if possible at all.
Again, this might also be a good opportunity to work on the communication b/w you and H (since you mentioned that was an issue and he is not quite the raving lunatic MLCer). If nothing else, it would help with co-parenting later, too. H likely does not know (or is choosing to be dense) about what stress this is causing you...he seems the type to back off and be Mr. Non-Communicative b/c he thinks he's doing you a favor and "making it easy"...perhaps if he was directed a little more to participate, he would?
Maybe he can help S14 pack up his stuff and room? A nice father/son activity?
As much as you can delegate to H, the instigator of this, the better.
