I apologise in advance for not having read the entire thread, but I can't go without contributing - and have a boatload to do today.
13 years ago, my house was so bad it could have been condemned. I mean that if SS saw the house, DS would have been removed immediately - that bad.
Emotionally, I was in a very bad place. Trying to clean caused me anxiety because I couldn't seem to make headway, and the environment itself made me feel subhuman. My XH did nothing to help fix the situation, only contributed to it.
Fast forward to now - after leaving (fleeing) XH, my house isn't a showpiece, but I learned that the environment was less about the mess around me, and more about the mess within me.
However, the behaviour that led to it is ingrained. So, now that I have the house under control, I have a personal list of daily, weekly and monthly tasks posted inside a cupboard door (so as to keep it out of prying eyes). I still tick off tasks as they are done, and give myself permission to skip each daily task one time a week.
This gives me a chance to put it somewhere other than bouncing around inside my head, and has reduced my anxiety about keeping house in a huge way.
My DCs each have their own task list, too. While our house isn't perfect, it is clean enough to be healthy and if I get a call from a friend (or anyone else) to say "I am coming over", then I can have the house presentable in less than 30 minutes.
It is important to look critically at your house, though. Does it look like that because you can't be arsed? Because you have more belongings than space? Because you are overwhelmed with DD's care? Because your partner doesn't contribute? Does cleaning it make you anxious? If so, do you know why?
If you have friends who you can be honest with, and who will help you without judging you, now is the time to go hat in hand and ask for help. Get together at a cafe and sit with (ideally) a group of 4-5 friends and ask for one day. Explain that you can't do it on your own, explain that you are trying, but ask them for one full day of help to get you to a place you can maintain. It is that part, the getting from here to there, that is the toughest part. That is what causes the real anxiety.
Also, try not to isolate yourself, it makes the developing mess less visible to you. Have a regular visitor, say a friend who pops by for a cuppa every Thursday afternoon. It will give you a fixed point weekly at which you say "back to my reset point". If the friend who comes by is one of the ones who helped with the big day of cleaning, they can also see that you are not wasting their time and effort.
You and your family are worth it. You deserve to live in an environment that calms you, your DD will fare better if the groundwork is set and she becomes part of the team early (as a toddler, for example, she can fold flannels with help, separate socks from the rest of the laundry and big socks from small socks, put one you away before she gets another out).
Many people see housekeeping as drudgery, but in actuality, it is self care. You can do it. It is a slow change, but you'll get there.