Telling you he booked as much time away from the kids as possible while they were being difficult with sleep... is just utterly awful.
So, he's admitting that he can't cope with the children because it's too hard... and you're doing a task 24/7 that he can't cope with even for short periods of time. Surely he's facilitating your life as much as he can - giving you lie-ins / time away etc etc?
I would like to get a job but how easy will it currently be? Also I will then end up doing everything and working.
Why would you be doing everything if you were also working FT? Both parents working FT means both doing 50% of the other chores. Essentially, both pulling their weight at home?
Why do you say that i) he wouldn't, and ii) you would have to accept that?
Is he a misogynist who sees housework as something beneath him because he has a penis? Or is he a lazy manchild who refuses to lift a finger because mummy always did it? Or is he the type who says he's earning more than you, so his job is worth twice yours and you should do all the housework?
The bar you've set for him is incredibly low. Stop tripping over it and start raising your expectations of what he should be doing as an equal parent to you.
If he's allowed evenings out to socialise, so are you. On the same terms as him. i.e. if he goes out before the kids are in bed, so can you. If he can stay out overnight, so can you. He wants you back by 10am the next morning? Then that rule applies to him too.
Tell him you'll be splitting the weekend lie-ins, and take up a hobby.