OK, so let's say you have 700 a month left over after your listed outgoings. At that rate it will take you approx 14 months to get out of debt. If your outgoings are accurate, you can set up standing orders so those debts get paid off earlier. If your parents are willing to postpone their payments, then you can clear your credit card in a few months.
Many people will say give up the cigs - as a smoker myself I'll leave that up to you, but one option might be to change to rolling your own.
I'm guessing from your car tax that you're driving a 1.8 litre, and doing quite a bit of driving. Consider whether you need that big an engine (is most of your driving in the city, for example) and see if it makes financial sense to trade down your car. Depending on its age it may not be.
If the petrol is for work, why is it not an expense? Is a mileage allowance built in to your pay?
Consider your socialising, and see if you can cut out one night out a month - maybe invite friends around instead.
Your life assurance is wonderfully low for a smoker (can you recommend where you got cover?!)
To be honest, I think you're misjudging your outgoings. With the figures you've posted here, you would appear to be 700 quid up a month, which doesn't explain your spiralling debt, and being overdrawn at the end of the month.
Keeping a money diary, and/or using software such as MS Money or any of the free alternatives would be a good idea for a few months. Off the top of my head I can think of a few other expenses that you haven't mentioned, like gifts/presents for people, TV license, internet access to name but a few. You haven't listed any money for one off things like upgrading your phone or buying the latest gadget or book. Not everyone buys these sort of things, but look around the house and see how many "things" you bought in the last year - MP3 player? CDs? Games? Magazines?
35euro a week for all your food seems quite cheap - are you counting the times you pick up a pint of milk in a petrol station etc?
You don't have to tell us, but once you get a handle on where the money is going, it will be easier to get a grip on things