Journalling....I was thinking of sending this to him in an email which is why I refer to h as 'you'.
Would this be bad to send to him? Maybe edit it heaps. There's so many thing I need to talk to him about practical/emotional/ to do with d etc and he won't talk to me when I address him.
Honestly, I'm not sure what sort of reaction you expect to get from that e-mail. If he's angry, then you just need to back off for a while and let him cool down. It is unfortunate that D has become involved - Maybe having her talk to a C would be helpful.
I think the 48hr rule defiantly applies to whatever conversation you have with H about all of this. I'd not send an e-mail though. If I got that in my e-mail, even when I wasn't angry, it'd be pretty frustrating to read.
Back off, give him some time and then see what happens. Work with D on your own for a while and make sure the most important thing is that she is not thrown for a loop by all of this.