Adopting the Ostrich approach is the worst thing one can do, letting debt accumulate only leads to the inevitable. The debt gets sold off to a collector. Speak to the card providers, be completely honest and explain the circumstances, record the dates and follow up in writing. A repayment program will be put in place, although be honest from the outset as there is no point agreeing to repayments which you will never meet. Therefore before speaking to the respective card providers, do your home work and have a plan in place (calculate your expenditure and what you can afford to pay) and then make the call.
As many have mentioned there are charities which can provide expert advice. Worth quoting when speaking to the card providers as well - It shows that you recognise and are taking a proactive step to resolving.