I’ve not got a lot of advice to offer, because what you’re going through is hard and sometimes there’s no easy answer.

I will however tell you from one stranger to another that the shame is misplaced. You have nothing to be ashamed about, because you’re doing the best you can. Sure, some hypothetical you has a shiny clean house and looks like they have all of their shit together but that’s not a real person, and that standard is not useful to hold yourself against. Your mil may very well have a spotless house but you can bet your arse she has other shortcomings where you are absolutely killing it.

Shame like this is almost always a learned reaction from some past events, and almost always it’s utterly unhelpful. You’re getting stuck in a shame spiral treating yourself like shit and then feeling so terrible that you’re in no position to dig yourself out. Try not to hold yourself to impossible standards. Treat yourself like a good friend - do what you can, and then give yourself a break. And try and recognise the areas where you’re doing pretty great, even though the house is a mess. Internet hugs.

I take it you work full-time, and your MIL doesn't?

If that's the case, then that explains perfectly why she has time to clean up and you don't.

From my experience:

Gently let your husband know that if his mom says something negative that he should not pass it along to you. What his mom said did not hurt you until he told you. That's how I taught my kid not to spread gossip.

As for your mother in law, if she comments that something is messy, hand her a broom. That's how I got my certified-clean-freak mom to stop making comments. "Vacuum's in the closet" was another one, but she was my mom, not my MIL, so it wasn't as hard for me. Sooo...have your husband do it. :)

I know this is not possible for many and also not a long term solution, but are you able to pay someone to do some light cleaning regularly for you? Not talking about deep cleaning but maybe like dusting and vacuuming and mopping? Having that structure might help - you know the cleaners will be there at 11 am every second Wednesday, so the task becomes doing some tidying before they come instead of this insurmountable shame mountain of cleaning your house top to bottom. As for your callous (in this instance) MIL, you can rest assured that she doesn't know what you're going through. It's up to you as to whether you believe she would have made that comment if she did know, and that should be the guidepost on how you go forward with her.

You might want to take a look at "How to keep house while drowning". I've heard a lot of good things about it.

The only person who has ever made snide remarks about my home is my cunty MIL. My friends know and respect me and expect my home to have some chaos because I do. I have people coming over tomorrow, and I promise there will be some mess or chaos they don't care about. My apartment is vigorously lived in, and it shows. People can respect that or not come over. Tbh, I suspect that maintaining that boundary is part of why my MIL hasn't come to see our place in the two years we've been here. That and our place is larger, nicer, and in a better neighborhood than her tidy little trailer, so she really has nothing to lord over us. Hopefully yours isn't as bad as mine, but yeah, I wouldn't respect her opinion. And don't get me started on the classism and ablism of someone not deserving to own a home they earned because you're gonna use it in an idiosyncratic way that suits you more than her. That's a gross thing to say.