I was on my own since I was 20 years old (no financial backing from parents or anything). While I was in college I took the train into the city to work an internship. I sometimes only had enough money for fare to get to work on payday, had to cash my check while at work so I could buy fare back home.
Also had to use one of those cash advance places that charged ridiculous interest rates a few times. Thankfully, each time, I was able to pay on time and never carried a balance with them other than the time between the advance and when I got my next check. Felt shitty to have to walk all the way to that place because I didn't have a car, and those places are never located in great parts of town.
I had my internet, and utilities cut of several times. Being at home with nothing to do and no electricity at night sucks... I had to read by candle light until i fell asleep. .
Plenty of times I survived for weeks on nothing but home-cooked meals of spaghetti, olive oil, salt, and powdered parmessan cheese.