Hi Bee
Sorry to hear about your financial problems, but well done for being proactive. I can offer a few suggestions, ... Alvin Hall has a book called 'your money or your life' which I found to be excellent.
Shop around certainly, but don't buy more than you need. About once every few months I try to use up all the food in the store cupboards and freezer ... you would be amazed how much food is lying there unused. Can you cook? If you can steer away from processed food you will save yourself a lot of money.
Cut your esb bill by turning off lights, tv etc when not in use.
Cut your heating by closing your curtains before dark (glass gets too cold)... make sure you never leave your doors open, even if you are only popping out to the car/bin/washing line for a sec.
Stay out of the shops as much as possible. If you don't go in, they can't extract the money from you. And you won't know what you are missing!
Allow yourself a treat occasionally ... decide beforehand what your budget is.
Look on rollercoaster.ie - /discussion on money matters for living on less tips.
Good luck.