Feeling like a bad CNA

I know this is only for period talk and pregnancy talks but I work in a healthcare setting, but I hope someone on here feels how I feel because I think it’s took a tow on my “health and lifestyle’. I feel like this facility I work in has gotten so much more difficult and I think it’s just on the staffing. On my second day of working my 3 12’s, for the weekend, a fellow CNA who works on a separate hall told me while clocking in for the morning that the scheduler told her that’d she’d be working by herself, for a hall that had 30 residents. I thought to myself how do they think that kind of staffing is safe for a 1:30 ratio. There were three girls on another hall, so one of the girls floated (worked on 2 halls, helping both of them). But didn’t make me feel any better. The next day, close to my end-of-shift I get a message from my scheduler if me and my coworker can stay till 9:00pm because she couldn’t find anybody till 9:00pm (note: I start the shift @ 6:30am and I have 3 girls on my hall..me, a cna, and a nurse aid in training) but me and my coworker, the NAT, had plans for Fourth of July already but I offered to stay till 7:30 and another girl who offered to stay from another hall till 9:00 but left at 7:15 because she had a problem at home, so I was the only one on the hall so before I had left, i did brief checks, made sure call lights were answered, and left a written report for the other night shift wing. When I left, I started to cry because there was no cna on the hall (even tho there was a nurse, but didn’t make me feel any better) telling my boyfriend on the phone there’s nobody to take care of them and so on as so forth about how I’m a disgrace. But my sister telling me that it wasn’t my problem for poor staffing. My coworker herself said the reason why she doesn’t take any extra shifts is because her other job took advantage of her and said that she wouldn’t let this one take advantage of her and thought to myself, for someone who usually goes in for extra night/day shifts, I felt like I was already being taken advantage of.