OP, I had one of those. After ds was born, he presumed he could carry on as he had done before. It was as if he was saying 'I've given you a baby now shut up and leave me in peace.'
I spent two years explaining to him that just because he worked 8 hours a day, did not mean I could care for DS 24 hours a day, 7 days a week, never have a break, and that he needed to help me.
I struggled on until I was prescribed antidepressents at which point I gave up trying, and me and DS (age 2) left.
Life is so much better now. Easier, better organised, less stressful, happier. The sad thing was when we moved into our flat, ds didn't even notice ex wasn't there, he had so little involvement.
Bizarrely, DS now sees his dad more than when we all lived together, because ex has to make the effort to come and see him. He manages a huge 6 hours a week (!) but it's better than it was.
There comes a point, you have to make a decision. A lot of men are just crap dads, selfish, thoughtless and lazy.
But if you are going to leave, the sooner you do it, the less impact it will have on your dcs. Good luck.