Food:
Definitely combine batch cooking with preparing earlier in the day. First trip to the kitchen, get all the veg out for your evening meal. Second trip, peel and chop a thing and repeat until prepwork is done.
Also, roast a MN chicken for stripping/ slow cook a pork joint for pulling/buy tinned tuna/ tinned salmon/ prawns. Grate a block of cheese. Get some wraps and pittas, salad bags, cherry tomatoes and dice a cucumber, grate some carrots. Then couscous, guacamole, hummus, other dips/ sauces and feta. Make up some rice, couscous and pasta salads. Come teatime you just need to stick it all on the table. And then put the leftovers back in the fridge for tomorrow. To change it up swap the meats, carbs, cheeses and sauces over.
You can grab a handful of the pork/chicken and whack it in the wok with some veg and noodles for a stir fry. Ready in mere minutes. Or with some onions, peppers etc and chuck in some curry paste and a can of coconut milk.
If you don't fancy chicken three days running then roast it on day one, serve with couscous or whatever. Strip and freeze the rest. On day four it's ready to chuck in a stir fry.
And deploy the slow cooker for other meals. Tonight spaghetti Bolognese is tomorrow's chilli.
Make a tomato base sauce and keep in the freezer in bags - passata, tomato puree onions, garlic, peppers, grated carrot and reduce. Get a bag out, spread on readymade pizza bases and top with mushrooms, lean ham, a sprinkle of cheese. Serve with salad.
Put something in the oven while the baby plays for two minutes and set the timer.
Keep the fruit bowl stocked and keep nuts to snack on.
Run the sink for the dishes while you serve so that the water is still hot when you've eaten and the dishes will almost clean themselves.
Exercise:
Get a baby carrier and a pedometer and set a target. Walk every day. It'll help motivate you if you're hitting your step target. Google sling swing dance, close the curtains and put some music on.
Take him swimming. You can walk around in the pool and the resistance will help you feel like you've had a bit of a workout.
Do "baby yoga". Get on the floor and copy him. If he rolls then you roll. If he crawls then you crawl. Lift him on your shins, above your head, do squats while holding him.
Carry him up and down the stairs with you. Do two trips instead of one.
Sleep:
I couldn't handle CIO. We coslept/sleep. Even if you curl up together on a rug or matress on the floor (make it a safe space first) for naps during the day, or just part of the night.
Try taking him for a walk in the evening. The fresh air might tire him out. Or walk him round the house in a carrier/buggy if he wakes. Change his bath time. Mine have both slept better with a daytime bath, as it seems to wake them up. And try to remember it's not forever (sometimes it helps, sometimes it doesn't).
DP:
Ask him to take the baby for two hours on his day off. That two hours is yours. A half hour bath and an hour and a half to sleep alone. You'll look forward to it all week. And once a fortnight on this day have a bloody takeaway. Give yourself a bit of the day off too.
Alternate with the dishes and serving . If you're cooking as above there shouldn't be too many dishes.
The best baby product I ever bought was the carrier. I can hoover and steamclean the floors with DS in it, and the noise helps him fall asleep for his nap, at which point I can lay him down and nap if I need to, or do a chore I can't do with him around, like clean the toilet or oven. I also wash up in it, do the laundry, wipe the cupboards, do the shopping, put the shopping away, do some of my food prep, lay the table.
He'll play on the floor while I chop, fry or take things out of the oven, and then go back in it if he starts fussing and I'm doing something safe like wiping the sides, cleaning the things I've used, taking things out of the fridge/putting them back. If I'm stirring a sauce or just keeping an eye on things he'll sit on one hip and I stir with my opposite hand standing side on to the hob.
I was an absolute disaster with my first, and we lived on takeaways for a year, the house was a mess, I was shattered and me and DH were not in a good way. It's far from perfect but I feel like I have more of a grip on it all this time around.