<human>: Can you condense the text into three sentences or less?

Within the past year or so, I believe my mom's mental condition has started deteriorating. I'm seriously concerned for her health and well being and so is my step dad. However, she has become extremely selfish within this past year and it's seriously wearing my step dad down. He's at the point where he wants a divorce and wants to move out.

 For some context, about two years ago my step dads father passed away and my step dad was obviously upset about this. My mom was very selfish at the time and tried to bring the attention to herself instead of his father. My mom practically pushed my step dads family away from him and they even told my step dad they won't talk to him until he leaves my mom.

 Now at the moment they both live on social security disability. My step dad tried to talk to my mother about how shes been acting and is always met with "I'm not feeling good, I don't want to talk about it". She also refuses to go to doctors appointments.
 Whenever my step dad and I mention moving out she says she's going to keep my step dads money. My step dad wants to go back out and work again just to get out of the house seeing as the only times he leaves the house is for walking the dog or buying groceries. My mom on the other hand almost never leaves the house.

 If my step dad and I do move out then my mom would have no one to help her. I believe her attitude has pushed away her friends and family so she may not have anyone to help her.

 I'm sorry if this is a messy post, I'm currently on mobile at work. I'm also hoping that I'm posting in the right place.
<bot>: My step dad wants to leave my mom and move on with his life and see his family again, my mom is practically black mailing him to stay.