I completely understand how you can get into a muddle with self employment and payments on account, plus moving house and the admin and expense that comes with that. I do it myself almost every January and July when the next payment in account is due, and despite being v intelligent, struggle to get my head around what years tax I'm paying!
Firstly I would stop worrying about the overdraft, you've spoken to the bank and arranged an agreed overdraft that is going to be in place as soon as they can do it, and reduced it as much as possible using your savings. So they are steps forward.
Next, how much do you have outgoing over the next 3 months, add up everything that needs to come out of your account, tax, bills, groceries, petrol, social activities you've already committed to.
This is where I find being self employed both a blessing and a curse, because as long as your mental health allows, what happens next is in your control! You know how much you need to earn, you know how much you already have, you know how much you charge, how many outstanding invoices you have to be paid. How many days do you need to work to make things right for the next 3 months, is it achievable? If it is, go for it, prioritise getting back on track, meeting your obligations and paying the minimum on credit cards until your cash flow is in a better place. If it isn't achievable, how can you make it so? Do you need to discuss it with your partner to get their input into restructuring things (even if they don't have a financial input), do you need to speak to the bank about restructuring your debts so they become affordable, or would your mental health be better off for closing the business and becoming employed and reducing your stress that way?
I think for me it can sometimes feel insurmountable but by taking a 3 month view of my finances and working out what I need to achieve I can normally start to the see the wood for the trees!