Well, you pay the bills in advance with the money you made from your most recent commissions. Five figures ought to cover it. Especially when there's effectively another person's salary coming in from Patreon every month.
You look for a cheaper property to rent for when that money runs out. With a parent who owns property, it won't be difficult to get somewhere as they can stand as guarantor. A two bedroom flat would be more than adequate for a single parent - after all, if any were to present as homeless to the council. they'd be doing well to get a three roomed property these days.
Once the money looks like it has genuinely run out and your accounts are up to date, you close the company and get online to claim Universal Credit. At the time of submitting the claim, if you have provided all the information required (such as said accounts and proof of cessation), you request a partial advance on the first payment. During this period, you put things such as expensive sideboards, desirable appliance brands and additional white goods in addition to the bare minimum of fridge and washing machine, works of art and designer clothing up for sale. As the adviser will require anybody with a child above 5 to be actively seeking work for the equivalent of a full time week (and be able to prove it), you complete your side of the jobseeking agreement and then you keep to it.
If you do receive any monies from self employment or work, you notify them at the end of each assessment period and provide evidence as appropriate and if any payments are due, you receive them the following week. It's beneficial to start your claim so that the assessment period falls mid month, so as to not fall foul of the two salaries in one period duck up where it automatically assumes that you have suddenly doubled your income. You also submit a claim to your council for council tax relief, as that's not handled by UC.
When you are in receipt of UC, the electronic award notice will tell you if you're eligible for free prescriptions and dental treatment each month. Make a point of getting your NHS prescriptions filled during that period and be careful to complete the back correctly, so that it is clear you are a UC claimant. Or, with the last of your money, buy a prepayment certificate for the year if it's not clear whether you will actually qualify. Unfortunately, any private prescriptions are not eligible. It might be possible for an NHS GP to prescribe them upon receipt of a letter from a private consultant, but it's not guaranteed, as it might be expressly prohibited under NICE guidelines or local trust policies. But it's worth a try. If discontinuing any medication presents a medical risk, it is possible to request referral or self refer to local Drug and Alcohol services with a view to detox/managed withdrawal.
You abandon any notions of being the sort of person who owns their own house, you prioritise rent, any proportion of council tax payable, child maintenance, TV license, alectricity and gas. You cut down to one phone contract, because you still need to have internet access in order to fulfil the requirements of the jobseeking agreement and to manage your claim.
And you get on with it. One of the best things you can do is prioritise healthy food that provides a good source of carbohydrate, vitamin C, fibre and B vitamins. Such things as jacket potatoes with cheese and beans make it possible to do so, rather than picking items that have very limited nutrition. Taking a multivitamin helps, too.