You can't control her reaction, but you can at least try to stay calm on your end. If she interrupts, let her talk and consider not who is wrong or right, but is what she wants something you're willing to do for the sake of your family. I'm not suggesting you always just do her bidding, but you're at an impasse right now and someone has to extend a gesture of good will, and you're the one here asking.
I'm no expert, but the two of you loved (and even liked) each other at some point in the past and now you both drive each other crazy and have a hard time remembering anything you like about each other. Often, it really boils down to one big thing that sets off this pattern. Often you tolerate a great number of small things until something big comes along and then all of those small things become intolerable as well. So far, the things you've mentioned all seem pretty small, albeit a little crazy imo. The crazy was already there when you still liked her, so what was the trigger? Was it a big move? a job change? The new baby? Maybe all of the above? -- The baby alone is a huge change even if health isn't an issue. Does she need help adjusting to motherhood?
Unless this was an arranged marriage, you knew her beforehand and didn't take issue with her need for cleanliness. If you think she's acting like a completely different person because of the recent pregnancy and she doesn't agree, you're just going to have to be patient with her and try not to make things worse while she recovers.