Your DH and MiL are engaged in triangulation, colluding in putting you down to make themselves feel powerful. It's toxic and it needs to stop. In fact, it's shit and he knows it is and was honest enough to name it to you!
He ignored your reminder of what you'd been contributing because he had a different, false, narrative ready to trigger his mother into calling to berate you for laziness. They are a pair!
He literally told you he was serving his shit up to you and that it was deliberate and intentional.
You were not being "annoying"; you were attempting to short circuit a toxic pattern of behaviour that manipulates facts to put you perpetually in the wrong. He likes you there so he ignored your truthful intervention.
I suspect this is a damaging pattern of behaviour he has learned in childhood and it is clearly well embedded now. You do not need to participate. You do not need to care what his mother thinks. If she calls, you can put the phone far enough away that you just hear quacking, not words, and wait for her to run down before picking up the phone to say, "Bye then, Sue!" before hanging up. It doesn't have to reach you from her.
He's a different story. He needs to understand that the way he speaks to and about you is unacceptable and is jeopardising his future with you and his coming child. He may well be stressed, but why is he pushing the relationship destruct button? Is that what he really wants? He could just be an adult and tell you instead of driving you away by making himself repulsive.
I'd tell him you listen to him feed shit to his own mother every time he calls her and for some reason she seems to lap it up, but you're a different person and you have no appetite for his shit, whether it's steaming hot and fresh from him or cold, congealed and recycled from her.
He needs to seek help urgently and change this pattern before he poisons a third generation. Let him know you won't let that happen.