Me and my daughter lived off of £5.00 a week for about a year a few years back when times were hard and I tell you what I can be done if you can cook your laughing lol.
We had 3 meals a day good filling meals.
We now live off about £20-30 a week sometimes less.
Good luck to you and keep us posted it can be done just shop wise plan what you can get for your money look online at the best prices ie tescol,asda,lidl,morissons and so on also we have lots of Indian supermarkets in our town really cheep for veg rice pasta good quality food better than supermarkets like tescos etc.xx