Why do people treat people bad

I've seen postpartum mother's who need advice help being told they have postpartum depression should be on medication or institution.

I knew a man who married and his wife wanted to move for her job and once they moved he had cancer and she was cheating on him and divorced him left him there to deal with the cancer alone. It broke my heart because he was a good man he fought cancer and married a woman who appreciates him and I'm so happy for him he moved back and has support.

But it's like why do people treat others bad I worked in my 20s and I have money saved I live with my parents and I'm thirty I live here because they are my family and I like to live together I talked to them about this and they said they are okay with this the house is spacious we have a guest bedroom in the basement and my aunt was fired from her work for having a toxic attitude and her husband divorced her for her bad attitude and her mom and brothers and sisters and cousins did not allow her into there home for more than a month because of her bad attitude so now she's here.

I don't know what to do but I feel like so sick so she arrives and is surprised to see me made a comment adult children should move out of their parents house.

So I noticed she's passive aggressive and she told me she thinks I should move out and that it's her sister's house and she can do anything she's been using the kitchen like it's her house using the washing machine dryer and I don't care but I do care that she is giving me these ugly looks that she doesn't want me there it's my parents house and they have told me that there house is my house and I've felt comfortable but with her here someone so blatantly saying I don't want you here it's made me feel like I can't leave my bedroom and she's said things when I use the kitchen why don't you kill yourself and leave move out and I don't understand why she's doing this I guess it's because she wants the house to herself my parents are mostly gone at work I'm at home taking college courses online and she's here but it's like knowing that someone hates you so much and you've been kind to them have nothing against them, respectful and they want you to die or to leave and I don't know what to do with this. This woman only does what benefits her and I'm scared she's using my mom.

So I'm actually thinking about leaving but I feel like this woman is doing things to make me leave and she's done this with everyone and until they see it she uses people and she couldn't use me I saw right through her and what should I do should I move out should I stay what can I do what conversation can I tell my mom?

I feel like I'm losing everything.

I have been here at my parents studying I was hoping to study and finish degree then work save up and move out my parents have also told me they are going to sell the house and retire in about two years they asked me if I wanted to move in with them but I said I'm unsure because I'd like to have my own place just with the prices of rent I can't if I move out I'd be like on my own and I start to get sad when no one's in the house and I will have to work to pay $2,000 in rent and I don't have time to study to do class my brother left his child In my custody so I'm raising a child and it helps because my mom helps babysit well it's her grandchild so they spend time together and she said it is welcome but moving out I don't know how to do it as a single mom I'm a single parent now and I have this responsibility and I don't like this living situation with this woman and child that I'm raising has to see her disrespect.

I don't know why this woman doesn't like me I cook I clean I help my parents I have an education I'm helping my family I'm raising a child I don't know what to do I'm nice to everyone I don't even know what to say to her just that I'm outraged at her disrespect when she was whispering that garbage I told her do not disrespect me and she turns it around saying you disrespectful you have been disrespectful since I came here and I couldn't believe it my mom came in said what is going on and she told my mom that I need to see a psychologist because what are adult children doing living with there parents and this woman has the nerve after everyone has kicked her out she has no where else to go my mom is doing her a favor and she treats me like this I told my mom that woman is no longer my family. mom said she isn't kicking anyone out that we have to learn how to live as roommates.

That's my mom's sister and I'm my mom's daughter so that's the situation what would you guys do?