If you have a caring nature, stick with it.
I agree that it's not a job for everyone, but if you're passionate about helping others, it's a very rewarding job. Those conditions are borderline illegal; you are not required to work whilst on your lunch break (or coffee break, for that matter!), although there are those who will "use" students and those on work places by taking advantage of their newness and unfamiliarity with regulations.
I'd report that workplace, or manager. That kind of thing is not on. I smell a rat!
I'm also curious why the place you're at stinks of faeces and urine. A small amount of unpleasant odour is to be expected, but it shouldn't be overwhelming if proper care is being taken of the residents. If you feel the smell is excessive, you can anonymously report the organisation to an independent body relevant to your state/territory. I've been employed for several months in high-care dementia, with a high incontinence rate and even "finger-painters" (people who dip their fingers in their own faeces and smear it over themselves), and I've worked throughout a gastro outbreak, and we have not had anything more than a mildly perceptible odour. That seems wrong.
In the right facility, Aged Care is a very rewarding (albeit demanding!) job.