Moshe: It will only get worse. Every skill you have will be utilized, far in excess of your job description or pay scale. The residents will drag you down. As they deteriorate they can't distinguish friend from foe, and one of these days you will face outrageous accusations against you from some resident. The management (and possibly law enforcement, depending on the accusation) will treat the whole thing seriously and, instead of recognizing the resident's condition, some or all of the blame will be laid upon you. You may face charges, you will certainly not get a reference from that employer! The building will continue to deteriorate. You've already mentioned the condition of the carpets, etc. Things are already spiraling downward at that place if they're not calling in "red teams" to clean hazardous waste (body fluids) and aren't replacing the carpets regularly. Yes, replacing.
There is more to say but I think this will give you the answer to your question. Run. Before you do, though, you may want to consider whether or not any aspect of the job has caused you injury or excacerbated an existing condition. State Disability kicks in for things like that in many places, not to mention Worker's Comp.
As far as helping beyond the scope of your duties (i.e., doing contractor's work so the nurses would be comfortable), it can backfire on you so easily! Yours was a human response and it may save them money but it wouldn't have helped you a bit had you been injured in the process or the repair gone faulty later on. Going beyond the scope of your duties is a negative thing when it comes to claims and compensation.
In other words, the deck is stacked against people in jobs such as yours. IMO, you should get out as soon as possible.