Your feelings are valid, OP. And I think other posters are being a tad harsh on you - perhaps because they also have DHs that don’t pick up the domestic slack and accept it or suffer in silence? Who knows.
I also have two very young children, both in nursery, me and DH also work full time in ‘big jobs’. The routine is relentless and when you’re out of synch or one parent starts to not do their parts, it’s not only exhausting, it’s ripe for building resentment.
There are certainly times when me and DH start to rely on the other more during times of stress, and it definitely leads to shitty feelings and arguments! It’s not OK, however, for him to leave you in the dark and not a) communicate with you or b) express gratitude to you. So he’s prone to go quiet and leave you to EVERYTHING when stressed? So what? That’s not marriage and that’s not parenting, so he needs to step up, the bare minimum being to communicate with you about it. Wouldn’t it be nice if we could all hide in our cubby holes when we’re stressed out.
For me the past few weeks, my DH has definitely picked up the slack for me due to a horrible constellation of illness, work stress etc, and he’s really been feeling the pressure with the kids. And I can plainly see that, so I’ve spoken to him a number of times to say sorry, thank him and let him know I’m working hard to get on top of things again. It’s not perfect, but he appreciates the communication and it goes a long way.
I’d be sitting your DH down when the kids are in bed and telling him how you feel.