Are you in receipt of PIP? If not, at least try claiming it, as its paid whether you're in work or not. It's meant to cover expenses for just the sort of things you need as a result of disability - such as a cleaner, getting deliveries, easy prep fresh food, dropping the washing off at a launderette for service washes and ironing.
Are you accessing decent medical treatment? If it's inflammatory in origin, there are a shedload of treatments beyond the GP saying 'oh dear, take some neurofen' that can completely change your life or at least make it more manageable. But it means insisting on a rheumatology referral.
Other than that, streamlining operations help. Get rid of clutter, unnecessary furniture, random stuff, the things that just get in the way. It's a lot easier to push a decent vacuum around a clear floor than it is to have to pick a hundred things up or work around piles of stuff. Have a dishwasher, don't have twenty plates that all need to be handwashed, have 10 (2 per person) and shove them in there.
Find the things that annoy you, the things that make a ten minute job take 3 hours and still isn't completed to your satisfaction. And find ways to eliminate or at least reduce them.
Does that baking tin take ages to scrub but still feels yucky? Bin it.
Is it tiring to stand for ages peeling potatoes in the kitchen? Sit down. Take them, a saucepan, a carrier bag for catching the skins and a good peeler in front of the TV. Or better still, just boil the buggers with their skins on - if the potatoes are cut in halves/quarters, they'll come off when they're cooked with far less physical effort, if you even need to remove them.
Is it hard work to stand there ironing? Pay somebody to pick it up and return it all perfect. Or do the launderette thing. Or lower the board, have a high power steam iron and do the minimum amount necessary sitting on the sofa.
Pay a window cleaner to do the outsides once a month.
Depending upon the specific needs of your DC, get them helping where they can - loading the dishwasher, getting a tablet out of the cupboard and putting it in the machine, collecting cups, anything that saves you bending down.
If you have a separate shower, use that in the morning to free up your joints. If you've only got a bath, look at installing a shower over it. Even something as simple as a thermostatic mixer tap takes out the guesswork and leaning over - you set the temperature, turn the water on and you're ready to go. Look into having easy turn taps, an extra handrail where you need it.
Take some leave and book a whole house clean, go and do something nice (with or without children), come back layer in the day to a clean house.
Get a litter picker grabby thing to avoid bending. A happy side effect is that most kids love using them - get two and somebody can help.
If you can do something standing up, try to do it sitting down. If you can do it sitting down, try it sitting down with your feet up. You might even be able to do it laying down - reading, homework help, cuddles in front of the TV.
You are probably super efficient at work, or can at least see ten things there that could be done better if you had your way. At home, you can do the same.
You've got this. It doesn't have to be Instagram worthy, it just has to run efficiently. You can do it.