Also I definitely agree that living on a shoestring is easy when you know it's temporary.
When you can't see an end to it and you want to get a job but you can't find one, or you find a job but then end up with the same amount of money after childcare, and your child in the care of others for 10 hours a day, it's hard and demoralising and makes you wonder why you bother.
Or you have a low paid job and think, it's ok, it's temporary, and they fill you with all sorts of promises about promotion but then after a year working there you're seeing people who've been in the company for years getting all excited about being maybe promoted to supervisor in name but not getting the new pay check until they've completed some kind of probationary period... And seeing colleagues on the same zero-hours contract as you get demoted to 1 day a week or 0 hours just because they've been ill quite a lot in the past month... it's just endless, and that's what's hard about being poor. The feeling that it's never going to end.
Also I've found as well that in desperation costs end up mounting up. You prioritise the stuff that doesn't directly benefit you, like bank charges, and debts, because if you ignore them they just keep getting bigger and bigger. I've had times where I'm so frightened to look at my bank balance because I know it's low so I don't look at it, and then something pops up like a charge which takes about 50% of my income out of the question. I've done things like cancel the direct debit on my utilities to get me through a rough patch and then ended up with massive monthly bills to cover the debt accrued from this and then no chance of moving to a cheaper tariff because of the debt.
You feel exhausted because you're working hard, not taking days off when you're ill because you can't afford to lose the pay, eating shitty food because it's cheap, expending extra energy on shopping around extensively with the purpose of finding the item which is the best value rather than having the freedom to choose the one you like and stop looking when you have found something suitable, cooking more from scratch, doing everything yourself because you can't afford the labour saving options, not sleeping because you're worried about bills, and then because you're exhausted you make mistakes and sometimes need crap convenience food because it's better than nothing and sometimes you're too tired to shop around and you just buy the first thing you come across rather than the best/most economical option, and so you end up spending more money you don't have. It's a cycle, and not one which can be replicated in a short amount of time. It's easy for people to imagine how they would do things but the way that you react in real life with all the stresses that build up isn't something you can plan or guess.