I need money quick what can I do?

I mistakenly thought I had had an extra payment from tax credits so took my daughter out shopping and bought her some new clothes and new trousers etc, for starting high school. I have had the cat at the vet and the car at the garage but thought 'Hey what good timing that money was!'. I have since discovered that it was my wages that were paid in and now don't have enough to cover my bills let alone eat for the next month. I have been looking online for instant loans for about �500 but they all seem to be asking to be paid in full the following month, which I could not do. I am a single parent and already owe my parents money for helping me out with the car a while ago (my ex was supposed to pay the bill but hasn't) so don't want to ask them. I am embarred that I have been so silly but am worried sick as my direct debits come out on the 1st and 2nd of the month. What can I do?