How much are you spending on petrol?
How much are you spending on food? What sort of food are you eating?
Are you buying random shit to make you feel better? Are you buying a Starbucks MegaSugarDiabetesGiver and a slab of cake each day? Do you go to the petrol station and pick up chocolate, large cans of Red Bull/Coke/etc and a massive packet of crisps whilst you're there?
You need to pay for petrol to get to work. Nobody needs to buy the other crap they sell, especially not at the prices they charge.
How much do you weigh/what size clothes are you? If you're size 32+, then that's a lot different to being an 18/20.
Walking doesn't burn enough calories to negate what you are eating if you're having sugary stuff or takeaways every day. Eating highly processed foods will make you feel like crap if you don't eat fresh vegetables.
Looking realistically, your bills are roughly half of mine and my income was nearly half of yours for two people and two cats up until three months ago. Now, if you're missing credit card payments/going into unauthorised overdrafts every month, that will swallow up far more money than you appear to have on paper. To tread water at present if that's the case, you must set up direct debits for the minimum credit card payments right now. That won't ever clear the debts, but it will at least prevent any extra charges
Look at what you are eating. We've already talked about the pointless crap, I'm talking about the actual stuff you have in meals. What do you eat? Lots of pasta? A handful of dry pasta is plenty. If you absolutely cannot cope without having a mountain of pasta and a whole tub of high fat sauce so you fall into a sleepy, post carbs slump, then the best thing you could is actually not eat it at all for a while.
Add a fuckton of vegetables to every evening meal. Do you eat meat? If you do, rather than going for a chicken curry/onion bhaji/pilau rice/meal for 2 from the supermarket or curry house, bung a single chicken breast (bought frozen in a pack, preferably, as they're cheaper that way) into a plastic food bag in the fridge with a couple of blobs of natural yoghurt and a tablespoon of garam masala in the evening. By the time you get home the next day, it will have defrosted and marinated.
Chuck it into a pan with minimal oil and let it cook. Whilst that's happening, open a bag of mixed leaves and put half in a big bowl, add cherry tomatoes, cucumber, that kind of thing (which will cost you about £2). When it's cooked, slice it up into bite sized pieces and put them on top. Add a good squeeze of lemon or lime juice - from a bottle is fine). Try to eat it slowly. You've just spent around £5 instead of more than a tenner from the supermarket or £20 from the takeaway. And far, far fewer calories with far greater nutritional value.
Rather than 'treating' yourself to shite that isn't making you feel good, look at 'treating' yourself to lean meat, to fish, to fresh vegetables, to fresh fruit for a sweetness hit. Enjoy meals for their appearance, their colours, their flavours, not their ease to cram down your feelings with.
Take a multivitamin. Odds are that you're low in Vitamin D, for a start.
Just a few days and you'll start feeling a difference. You won't magically become slim, but food should energise you, not sedate you. Force yourself outside for ten minutes during the day, even if it's pissing down. You need daylight and fresh air, even if it is standing underneath a tree in the pissing rain, it's better for your eyes and body to do that than stay inside all lunch.
In the longer term (such as the end of the month when you haven't dipped into credit cards as much), see how you feel. Has that change in habit at the petrol station/what you have to eat become easier? Do you feel a bit better?
What other exercise/activity have you enjoyed? Do you like being in water? Could you use the fiver you've saved on one meal compared to previously to pay for an aquafit session in the local pool this week?
Have you ever used a gym? Paying a membership might seem like another expense, but if you are so unhappy about your weight and mood, perhaps your GP could refer you for exercise - some places do that and it means you get reduced costs or even free use at certain times.
There are many things you can do to start feeling better. But you have to try them - not just for one day, you need to keep doing them for a while to be sure they'll have an effect. And once you're feeling better about yourself and in yourself, maybe the other things won't seem so unsurmountable.
You might not be comfortable with this. But you sure as hell aren't comfortable with yourself right now. So try a different sort of uncomfortable.