Not much gas left in the tank

I've been nursing about 15 years. I've been through some hair situations and I'm no stranger to hard work, but I gotta tell ya this last 6 months has just about kicked my whole ass. Administration in my building has pretty much checked out and stopped answering my calls. We are perpetually under staffed, under supplied and cannot get the support we need from other departments. I'm not as young as I used to be so flip-flopping between shifts to ensure coverage and just physically lifting a lot of these folks unaided because there is no one else to do it is starting to take a physical toll. My back and knees are starting to complain to me pretty eloquently. Ive always been a pretty patient person but I've noticed over the last couple months my temper is almost literally on a hair trigger. This is not helped by the fact that if I don't yell and act aggressively I'm almost completely ignored by staff not working on the unit. I've been doing this long enough to recognize burnout when its taking a dump on my chest. I know I need a break, and I probably need to be cycled off the unit so someone fresh can step in, but thats not going to happen. I can't in good conscience quit, but I fear the quality of my care is suffering. There is no end to this in sight and Im not sure what to do.

TLDR: Tryna beast mode this shit but my inner wolves are more of a couple mentally challenged geese that kind of need a nap.

Edit: Front page huh? Cheese and crackers. Well I truly appreciate all the kind and encouraging words from everyone. They really have helped to bolster me in a weary moment. To all those telling me to quit or move on, I understand where you're coming from, and in any other situation you would be absolutely correct. Here is how this situation is unique.
1. What I do is sacred to me. It sounds dramatic but there simply isn't any other way to put it. Providing care to the sick is a holy act in my little soul. I can't walk away from that. Me staying is not born of some loyalty to a corporate monolith or delusion that I'm valued by my company. Fuck my company and fuck the people that run it. I stay on for the patients. I can't leave them in need any more than I could leave one of my kids in need. The idea does not compute. It's probably not the wisest or most healthy answer, but it's the only one I have.
2. Make no mistake. This is a singular moment in history. This will be written about after we are all gone. I'm under no illusion that I will be in some history book, but I'll be DAMNED if I reach the end of my life with the knowledge that when the call went out and I had the chance to help I did anything less than my utter best. I will continue showing up to do this job until these old bones wont carry me any more. I will not quit a moment before that. And should I take sick and this is what spends my life, then I'll end my days calling it work well done. This isn't a task I'll walk away from until it's done. When we have a vaccine and this sickness is being managed with success I will take a long rest and be proud of what I did. Until then there is no quit. I may break, but I wont quit.

Again thank you everyone for your kind words, your concern and your guidance. All of you stay safe, wash your hands, wear your mask, socially distance and enjoy your Thanksgiving.