I'm glad that you can see how untenable your situation is and that you's be under so much less stress without him.
I work in the same field, and without the support of my DH, I'd be a basket case by now
and that's with grown up kids !
The hours you are working, the lack of sleep and then the abuse you are getting, from the one person who should be your biggest supporter, is horrendous.
He does not respect you
He actively seeks out ways to make your life harder
He won't even look after his OWN kids so you can sleep !
He won't pay childcare for HIS own fucking kids !!!!
He wants you to feel like shit, all the time !
He cares more about 'getting one over on you' than anything else
He thinks all childcare, cleaning etc is beneath him !
He is showing your kids how to abuse you, every, single, day.
He sits on his lazy fat arse, waiting for you to come home after 13-14 hr shifts (saving bloody lives and coping with deaths daily ffs !) just so he can say you're not good enough because you haven't done the cleaning ?????
I know it's tough, but spill the beans to your mum and leave him now
You deserve so, so much more 