You obviously can't afford this private school. If you insist on it, you will have to make some drastic cuts elsewhere.the crazy food expenses are the easiest to address. Like the restaurants will have to be avoided, and you should also cut the groceries into half. 3 people should be able to eat on 5-600 easy. Why is it so high? Figure out what you are spending the bulk of the food budget on ( meat? Snacks?Prepared food? Perishables? ) and it will be easier to manage it.just write a list of the favourite meals the family is eating and cost them. If dinners are around 5-10 you will need to reassess how the rest of the food money is spent. (for me it was too much meat and too many perishables which we ended up not eating. Once I understood what was happening, it was easy to cut back and change my shopping habits)
With clothes I find that the best way to keep expenses reasonable is to write a list of the types of clothes we need: ie school clothes for the kids (4-5 sets), home clothes( 4-5), cute going out ( 2-3), formal going out. (1). Etc. I organise wardrobes frequently, so I know exactly what we have ( too many clothes) so I am not tempted to buy more. I also buy kids clothes at the end of the season from the clearance racks (the next size). I find that kids don't need a large variety, they have their favourites they want to wear all the time. For work I recommend a 'uniform'. My boss calls me the queen of frocks, but the reality is I have only 6 very nice dresses ( from the clearance racks of course). I find dresses easier, I don't have to worry about ironing or matching parts or whatever, it takes me 5 minutes to get ready and there is less laundry to do.
And what is the miscellaneous category? If it is entertainment, presents, toys, vacations, those can be budgeted for.
If it is just you and the kids, you should be able to control it, there are a lot of obvious places you can cut expenses, it is now your decision how you spend your money.
You mentioned there is a lot of stuff around. Is there anything you can sell to start an emergency fund with the money?
I wouldn't touch the retirement funds. Could you pay interest only on the mortgage until you get back to your feet? Refinance to get a better interest rate? I personally would attack the expenses you have control over (food, clothes, misc) and renegotiate the fixed expenses to see if you can get a better deal on them.