Maybe on the weekend you guys could leave the messy house behind & take baby Zac to the park for a picnic lunch.
Things feel different with a NB out doors. They calm easier & the crying isn't as intense.

The bath/shower with baby is a great idea too. I used to do this alot.
I also used to have a shower every night after all babies were asleep & just sit in there by myself for at least half an hour.

Maybe find something to do, just for 5 minutes at a time that gets you out of the house. Maybe some gardening or something? I started stupidly smoking again a few weeks after DS was born, just so I could shut the kids inside & go outside for 5 minutes alone. I wish I'd though of something constructive like gardening, lol. But I usually found the need to escape at night. Things are harder at the end of the day.