I remember the blur of those days, similar ages I think (oldest turned 7 when DC was born)...it does get easier, a while off for your just yet but I've just sold the pushchair and the last potty has gone, it feels odd.
I would say, don't aim for perfection, some days survival is as good as it gets and actually getting the oldest to school (on time or not) is an achievement.
I always used to have an emergency meal in the freezer (chips, frozen veg and chicken dinosaurs/ fish fingers), baths were reduced to twice a week if we could get away with it. I bought enough uniform for the ones at school to last a week so if I couldn't get to the washing machine it didn't matter.
My other life savers were Ocado and accepting every offer of help, all my freinds and family know thier way around my kitchen enough to be able to make a hot drink and even a lunch. They don't do it so much now, but in the baby days it was great (they didn't mind).
The slings were great, I got DC4 up on my back as soon as I could (get advice on technique from a sling library on this) so I could get jobs done with him up there.
This too shall pass as they on mumsnet (or they used to anyway), this goes for the good bits too, so sometimes you have to remember to stop amid the mess and enjoy the cuddles when they are so small.