How do wives to blue collar husbands do it?

I am taking care of my son alone for 18 hours a day. 18. Hours. My husband gets home exhausted. He’ll try to help but he is so tired that it usually ends in arguments. He does night routine every night but there is a cut off, if DS is not in bed by 10, he refuses to help (which I partly understand because he needs to sleep but that doesn’t make it any easier). I now have sole responsibility of night wake ups and he refuses to help. He says, “I’m going to bed at x o’clock no matter what”. He’s stopped doing chores regularly. I am drowning. I am doing 95% of everything. My child is not the problem to be clear, I am just exhausted. I am also in school full time but have no time to work on it since the only time I get to sleep consistently is during the day but my husband got upset at me for not doing my schoolwork during the day (while my son naps) so that he didn’t have to help as much. This is a far cry from how we functioned before this new job. We used to have a great routine down. He would help with everything and chores were equitable. I had time to do my schoolwork and relax. But this new job ruined everything. It’s a pay increase but I honestly prefer struggling and feeling better mentally than how things are now. How do you ladies do it?!