At my poorest (long before kids thankfully) i would often have no money at all left once the rent/bills were paid - i reached a point where i had only the bits and pieces from my pantry left to eat (and no money to buy anything else) so i had lentils and rice with various condiments a lot. Once i had to search my flat for lost coins to get something to eat and found just enough for a loaf of bread. I had to pay for it with mostly 10c coins and then live off of that loaf for days.
A couple times i had to ask others to buy me food - which was hard for me as i hate asking for help.
I walked everywhere because i couldn't afford to use public transport too much. I walked to the markets every Sunday (for cheap veg) and that took around 1.5 hours one way. To the grocery shop was about 45 mins. To town was about 2 hours walk. To work was about 45mins - i was very fit in those days.
For a long time i had no couch or tv - only a bed and wardrobe, a few kitchen items, a deck chair and dodgy table in the whole flat.