You are doing brilliantly - everyone is still alive and healthy and can wear less now it is summer. You need your sleep and energy for the baby and everything else will just have to wait. LIfe is just not like the adverts (except the one where the friend says the flat has been robbed cos it is in such a state.) Life is just not like that.
Washing is the bane of oall our lives. Can you buy your way out of any of this? Can you tumble dry laundry / send out your washing to be service washed & dried/ buy in a cleaner for a few weeks or a few blitzes? Stop ironing if you do that, or promise yourself ou will do that. Ironing piles are just sources of depression - just put it away and nobody will ever know it's not ironed. Are the kids old enough to play games to help you move stuff - choose thier own laundry out of the pile / pick up ten toys each? Find 5 things to put in the bin? Can you have every meal as a party and use paper plates and cups? Can you cook a lot less - meals can be very nutritious even if you didn't slave over a coooker for ages. Sandwhiches are ace. As are 'feasts' - basically a weird collection of all the things you can find in all the food groups - put it all out together and call it a feast. You get good food down the kids and they think it is a treat. We did this a lot when we were broke and the food we had in the house did not necessrily all go together to form a recognised meal.
Do you just have too much stuff around that needs returning to its right place? Do you wash the kids clothes too often? Can they wear everyhting for a day longer and so reduce the amount of washing you need to do.
Go now and pull out three new binbags. Fill one with clean laudry (from the pile or the drawers) and just hide it somewhere for a couple of months till youfeel better. Fill one with toys that are lying around - they won't even miss them, and if they do just murmur that they must be around here somewhere - if they tidied up they might be able to find it. And fill the last one with other things that annoy you (no, not DH or the DC's...)
Eat outside to save the mess in the house. Go for walks with the kids so they are messing up the park not your house.
Go to other people's houses so they get the mess not you (you can reciprocate when they need the help). Take up aevery offer of help - others minding the kids / coming to visit - make sure they wash up / make you a cup of tea instead of holding the baby. If they do insist on holding the baby - take the chance to do some jobs - they may feel guilty and try to help you.
Be kind to yourself. In six months time, you'll wonder what you were upset about. Nobody will have died of nasty dirt-related diseases, and your friends / family will have realised that youare not supermum after all - you are just like they were - even though they look back with rose-tinted glases.
But most of all - get all the sleep you can at every opportunity. If you have an option to sleep or clean up - choose sleep. It will make the rest of the time look better.