RN supervisor LTC

Hello. I accepted a position as RN supervisor in a LTC facility. My background is in ICU and Cardiology, so I have cared for a lot of geriatric patients. I feel my critical thinking skills, along with the fact that I am a very caring individual, make this an excellent area for me to excel in. The problem in LTC is that the facility I work for is way understaffed, IMHO. I have addressed this with the DON, since I am under her supervision, and she doesn't see that 4 nurses caring for almost 200 patients, along with 5-6 CNA's as a problem. She states, "We only had 3 nurses when I came here." Well, I have been stuck numerous times working the medcart, sometimes on a hall all by myself with 70 patients and 2 CNA's, and RN supervisor of the entire facility at the same time. Talk about SCARY!! We have had numerous falls lately, and I blame a lot of them on being understaffed, but no one listens to me. I worked way too hard for this nursing license to lose it. I LOVE my patients, and they deserve much better care than this. I am so mad and sad at the same time. I love my job, but can I, and should I stay? Please give me some honest advice.

Thanks!!!