I’m not really the correct person to answer this, since I’m not struggling to the same degree as you are.
However I once heard a good tip on how to save money. Most people, when they receive their salary spent it first on the necessities (food, rent, etc) and then save the remainder (if anything is left). But instead you should first save a percentage of your pay before spending on any necessities. That way, your brain will try to make the best use the remaining money to survive the best it can