Sadly, this is the nature of the beast with regards to LTC. Today's LTC patients generally require as much care as yesterday's acute-care patients, especially when you work at a Medicare facility, yet the NH is staffed as though the patients are generally ambulatory and need minimal ADL assistance. You have too many residents to be responsible for, especially when you want to give them the care you know they should be getting. Unfortunately, the realities of LTC often force you to prioritize what care is absolutely necessary, and what can be blown off, at least short term.
You cry because you know these residents deserve better, and you want to try to pick up the enormous slack left by the industry as a whole. Unfortunately, you are only one person, and you're not going to be able to do it. A DON that I respected greatly told me one time that there never is, and never will be, enough staff in a NH to give truly adequate care to the residents. She was truly sad about this, and she eventually burned out of LTC.
As far as your staff goes, I don't know what to tell you there either. A CNA's work ethics greatly influence the quality of care that you CAN give. An awesome CNA will walk on coals to ensure that at least the resident's basic needs are met, will function as your eyes and ears on the hall, yet not step outside of their scope of practice and create more headaches for you as the nurse. A bad CNA will just frustrate the hell out of you, since disciplining CNAs is extremely difficult in what is essentially a "buyer's market" given the chronic short-staffing in LTC and in nursing in general. Time you spend counselling or writing a CNA up is time away from patient care, and in the people that really need discipline (those willfully not doing their jobs), it doesn't do much good.
In my state, we use CMAs in LTC, and they have a fairly broad scope of practice for UAPs. CMAs are definitely a double-edged sword. While they take a huge routine task off of the hands of the charge nurse, there is plenty that can go wrong with medication administration, and a poorly-trained CMA not only makes more work for a charge nurse, but can be an absolute menace. But for better or worse, LTC nurses here are dependent on them.