I always feel jealousy is unreasonable, it is an ugly emotion and not one I have felt as an adult.
However it must be nice to have the option not to work. People who can comfortably afford to not work have more choices about what they do with their time but that depends how motivated they are.
For myself, I really enjoyed work, particularly as I got older, was more experienced and confident; I was fulfilled, met interesting people, wouldn't have wanted to stay at home but would have jumped at the opportunity as a young woman. I can see both sides.
You said: "....work a 12 hour shift where i get told off as i havn't been trained properly."
Is there no possibility of you undertaking some type of training which would enable you to get a more congenial job? 12 hour shifts don't sound much fun, even worse if you're admonished (that's bullying). Think about it, look at evening/day classes and see if there's anything you fancy.
In the meantime, take care of yourself, remember you can only do your best and something good may be around the corner.