I think I have to quit my dieting

cheat meals should be once a fortnight if not once a month, more than that and it's easy to over indulge and go back to your unhealthy diet.

i know what it's like being on low income and trying to be healthy. I don't believe for a second bad foods are less expensive than healthy ones however. you just need to watch your portions more and bulk things out with pulses and veg. You can also use 'meal' ingredients as snacks, again you just have to be abit daft and try things together.

For instance
pepper, carrot and celery sticks with humous (which you can make yourself from a can of chickpeas, youtube this) or healthy nut butter (like Meridian peanut butter, pb is quite high in fat so you want to watch how much of this you eat, proper pb with just peanuts in it is quite low in calories tho and has no added sugar so 30g goes a long way and tastes devine once you get used to the taste without it being overpowered by sugar).

instead of normal bread, have cloud bread (also called oopsie bread), all you need is cream cheese (like philidelphia) eggs, baking powder and salt and if you have it psylium husk thought it's not essential, it just adds fiber.
http://www.food.com/recipe/oopsie-bread-497736
this is GREAT with easy spread butter and Jam

buy frozen veg, they last longer and they are frozen not long after picking so are full of nutrients. you can make cauliflower rice and add in peas, bacon, scrambled egg etc, anything you get from a takeaway, it looks and feels just like rice but not as high in carbs. i love this. I defrost the frozen cauliflower in a pot of hot tap water for 5-10 mins (or longer if i'm preparing something annoying), then stick in the blender, blitz it so it looks abit like rice, then fry it in coconut or olive oil, move it about every so often, when it starts sticking it's ready.

You can have scrambled egg with just one egg and add in pepper, hot sauce (or any sauce you like) onion etc

you don't have to drink straight water either, there is this misconception that those 9 glasses of water a day has to be JUST water. If you are used to drinking lots of caffine, then drinking your usual amount of tea and coffee WILL NOT dehydrate you, your body is used to it. Green and fruit teas also count as water. Keep away from carbonated drinks, even diet ones and also squashes/diluting drinks as these have lots of sugar in them, have them occasionally but not as your main 'water' intake. You could try zero sports drinks (where there is virtually no calories, that add some flavour and electrolytes, they're quite expensive but are good every so often as something else to drink. and adding in citrus slices to flavour your water is also nice.

banana makes some awesome icecream by itself (google blogilates for some great receipes using 'weird and 1-3 ingredients only) and you can add more flavour using stuff you've probably got in your cupboards, yoghurt to bulk it up abit (or must more bananas), pb, other fruit, dessert sauces, nuts and seeds etc.

yoghurt with nuts and seeds, berries and a little honey *drools*

if your stuck for inspiration when there's not much in the cupboards, google what you have most of say: cauliflower recipes, and see what comes up!

good luck with everything

Overwriting slightly sarcastic comment. Keep your head up, kid. Everyone goes through hard times. You'll figure it out and be okay.