Crikey - don't apologise! It sounds like you are having a hugely hard time and DH shuld be pulling his finger out. I'm due tomorrow and on the first few days of ML and have just had a very helpful text from lovely DP, telling me to put my feet up. Which is very sweet of him and all very well, but the house is a tip and we will still need something for tea, and clean clothes etc, and he isn't any more likely to do that than usual if I do sit around for the afternoon!
I agree with minipie, "man up" is definitely the phrase, but possibly he needs a shove to do this. Unfortunately, your body doesn't actually just shut down when you need it to: it would be helpful if it did, but it is usually entirely possible to soldier on for an age and feel worse and worse - you do sometimes actively have to draw the line and say stop. At my past few MW appts I have been absolutely amazed that my BP is perfect and there are no problems, when I was really stressed out at work and knackered at home and just wanted someone else to tell me to stop - but no-one did (in my case because no-one would be that brave or stupid!).
Draw the line; you don't have to ask him not to go out (I would resent having to do that), but you do need a clear list of what needs to be done for the household to continue to function, and you maybe need to help him reach his own conclusions about what he should be doing in that direction. My DP is lovely but good at avoiding stuff too and I don't want to make him feel bad by asking/telling him to start pulling his weight - it is always better if he decides to do stuff himself. I tend to say things like, well, once DD is in bed there is only one hour to get all of this lot done because then I will need to be in bed - and I don't think it will all get done in that time, so what should we do....??? And a nice DP will hopefully take the opportunity you have given him to Do The Right Thing at this point.
And then, on your part, perhaps you do have to let your standards slip a bit at this time? Maybe the list of "stuff which has to be done" needs to be edited so there is nothing on it he can dismiss - if it all has a reason and a deadline it's quite hard to argue with.
Hope you get it sorted and get some rest OP - and get well soon too!