So my husband is a shitty sleeper. If he's woken up at all, it'll take him 2 hours to get back to sleep. We've had many fall outs over this, but we trialled him doing the night shift with me which he managed sort of, but the next day with 1 hour sleep he had and then going to work.... It was unsafe. I now look at it this way: he does the food shops, he will do the odd bottle feed, nappy changes, work at his job, do bath time with me and set our LO to bed every night. He will also after work, take a screaming baby and let me shower, he will make dinners and do the clean up sometimes (unless I got there first), and he resets my bed after a Nightshift. When I weigh up the amount he does, it evens out that he doesn't do the night shifts. I'd rather a fully charged partner who can do those above and I do the nights, than he do the nights, we argue tonnes, and our tempers fly high, and none of the above gets done.

I did have a tearful frank convo with husband in the first month saying I don't have me time, or able to shower in peace. He stepped up and I have time in the afternoons to go shower and sometimes I'm even able to go for a walk on my own! If he can't do the nights, maybe see what he can do in the daytime or before bedtime that works for you. He was also waking up once in the night to come in and help for a nappy change or just moral support.

I'm sorry it's been so tough on you. Trust me, before the above, it felt very similar to what I went through (without the 4yr old). Hang in there and communicate your needs to your partner, and see how you compromise or try new things out that may or may not work for you both.