Oh Neptune
He sounds like my FIL.... he's had longer to accumulate stuff and it is scary bad but he really has no idea. I don't know how my MIL has put up with it for so long - I do know she has little breakdowns every now and then. Gosh I do too and DH only has slight tendancies in that area.
He does need a kick in the pants somehow or other so he can get his priorities straight! All the best - we're all here for you however we can be. I hope you can get through to him.