Help! Trying to move Mom from her house that is in bad shape and too large to take care of to independant living apartment.

This has become a big fight. My siblings think it is a good idea but won't take the initive and support me. They want me to be the bad guy. Mom thinks she is no longer wanted and threatens death or suicide when the topic comes up. Keep in mind she has always been a negative controlling person her whole life. Dad was never home much just to avoid her. He passed in 1989 and she has been waiting for death since. I used to live with her until 2001. She had me on the brink of suicide myself because of the negativity. The house stays dark and she never leaves. She just sits there. I tried to get her help but she refused it and blamed all her problems on us. The house is in very bad repair and is very costly to heat, propane heat. I have grown tired of mowing 2 acres of grass every week, not to mention the high property taxes that I pay on it too. She lives in a very high tax area. I took over the ownership of the house in the mid 90s because she couldn't afford to keep it. The costs and stress of keeping it have become overwhelming to me. My siblings contribute nothing to the cause. I found a apartment complex in the same town that is hud sanctioned. The only thing she would have to pay is a small rent fee which is reduced by any medical bills that you have and she has a lot and electric. Basically she wouldn't have any rent. It is smaller to take care of and heat. For every positive I point out and what I could do to acommodate her she finds a negative and says no. She has it in her head (she is very strong minded) that dad wants her to stay there. After the last discussion about she threatened death once again. It is getting old. I am getting frustrated with her and my useless siblings. Any suggestions? Just walk away and let her sink with the ship? Thanx in advance.