Do a 180 on the rooms he sees. Livingroom, kitchen, children's rooms. Spend 8 hours on it for yourself.
Get rid of a lot of stuff if you can and it will be easier in the future. This is where your sister can help you. Probably she wants to help and doesn't know what she can do. Tell her you need and want help on this soon.
Yet don't beat yourself up. His apartment is likely slobby as hell. He doesn't have all the kids' toys there. And you're not over there looking at it.
It would make me want to do it so H could not take a "sympathy" attitude towards me. I would find that very motivational unfortunately.
Also, he may feel a lot of guilt. Who knows? If his depression comes across as numbness, callousness and anger, it's easy to cop an attitude with "female depression" that looks like exhaustion and tears. F him!
