I didn't manage my big catch up last night but have just woken and read your post, WG, and thought I would try to reply to you.
I don't think one can underestimate the strain that small children put on a relationship and it is very common for people not to get on when they are small. I think many of us on the thread have struggled with their other halves over the last few months and it is to be expected. However, that doesn't make you feel better, so I'll try to get my practical head on.
As you know, DH and I have not been getting on well of late but what really helped this week was going out without the kids and chatting about it over dinner without accusations flying. Is this something you could try? Could your dad babysit or, if not, could you take madam in her buggy and park her in the corner? When Lucy was small, we went out a lot on holiday with her in the buggy with a jacket over it (like a parrot in its cage) and she eventually went to sleep. It was like being a proper adult having a civilised night out and we managed it in some smartish places. It just is easier for us to talk on neutral ground and if you dno't have an onhand babysitter, it might be an option for you to give you a break from the house and let you talk openly with DH.
When I was in the throes of light PND with DD2, I was weeping on my GP about Andrew's uselessness and she said (which is very true), that as a 40 y old man, he must be capable of basic domestic or child tasks (even if he does not do them my way) and I should ask him to do a certain thing and then let him do it. I have tried to do this, as in common with other men he only notices when things aren't done, and it does work. It means that as a controlling person I have to relinquish the need to have everything my way, but at least I feel he is contributing. Is this something you could try - ask him to put a wash on (pre sorted in my case, so my woollens don't end up doll sized) and hang it out, do a shop, amuse madam for a couple of hours while you rest?
Fixing sleep - as the mother of a 5 year old, I am sorry that I am still struggling with this one, but it does get better. With some children, you have to work hard at resetting their sleep patterns, but it will get easier. Lucy still isn't great alas but has better periods. Can you talk to him and explain that so you feel more united about it? Huge amounts of sympathy as I know madam has not been great at sleeping for a long while though.
Food - we never eat at the same time as our kids because of DH's job. All mine have spent long periods sitting in the high chair eating finger food while I do things in the kitchen and chat to them. It's the reality of family life here and something which still carries on as the girls (3 and 5) can get on with things without me whereas I need to be able to see M and that means being sat in his chair. As for what she's eating, could she have your leftovers heated up or if not, how about easy things? Frozen veg are your friend so whatever you have, you can pop some peas or broccoli on to go with. Pasta and pesto, steamed fish, baked chicken, baked pots and cheese, beans on toast, scrambled eggs, soup and curry all well received here and can be done with minimal effort. She won't starve, so keep offering different things, don't show frustration if she won't eat and don't worry too much if she turns food down.
All will be well. Promise.
Big love to you my darling. And to everyone else. Still haven't caught up but will ttry over Easter. We're at the outlaws, so I'll need something to take my mind off them.