My sister never asks for favor she demands it

I used to be very close to my sister when we were younger but in last couple of decades (I am 48 she is 46) she changed a lot. I feel like I don't know her or understand her anymore. She is beautiful, smart, young looking woman but extremely insecure for some reason. When someone is sick she can be very pushy in giving often unwanted or not asked help, she is so determined that she needs to help no matter what you say or do. A lot of times, it doesn't end well or sometimes it does but still with some bad consequences. Sometimes she seems to desperate to help when someone is sick she will go overboard and can be tiresome. That is why I never ask her for help. That and also the thing that she will mention that over and over again later. She will also help with other stuff, bring food if you need it (cooked by her, she is great in cooking), medicine, everything. She always tries to be very helpful even if you don't ask her. On family holidays I would bring like juices and cookies I bought, she would bring whole great meals and salads and everything. If you are sick she would somehow find the way to get you to all tests possible.
What bothers me is that she will help you if you are sick but she never calls me just to chat, she is never there just to have fun, like we used to once long time ago. She is always super serious and calls me only when someone is very sick, dying or died. That is why I literally panic when I see that she is calling me.
On the other hand when she needs something she doesn't ask, she demands. If you are not sure you can help or you think it's too much, she demands, orders you, screams, brings out whenever she helped anyone ever, and even threatens (like "that one will die if you don't do that for me", because well there is always a connection). For example, she once wanted me to take bank loan for them to buy a car. I said I don't feel comfortable as I don't know if I can keep my job to pay rates and I think they should buy their own car. That resulted in anger and threats that our parents will die if they can't visit them often by car. I felt extremely uncomfortable by that.
And that always happens. She demands, orders, then threatens, finally cries and mentions what she did for everyone ever. It's got to the point I am avoiding her and dread her calls. She is very pessimistic and sees everything very dark. I am suffering from depression and anxiety for decades and I am struggling for long time to stay positive and not to panic and to bring joy at least if I can not help. I am exhausted. I had times when I was so done with everything, I wanted to give up. I live in horrible country and I can't even leave now. I am so tired. I am single mom. I want to help but if I can't I just try to make people feel better at least. But with her it doesn't work. Once she was hysterical and crying because she felt "useless" again and I talked to her for hours to make her feel better and to calm down.
But when I feel bad she just tells me to "stop overreacting" and apparently I am "boring".
She sometimes demands huge favors and when I try to reason how much I can do, she screams, cries, threatens that if I don't do something horrible things will happen. If I do not say I will do everything she asks, a lot of times, she just does it herself. But I know I will hear about it later. A lot. I don't understand her. She is upsetting me. I can't even talk to her, I am shaking after every talk to her, I feel traumatized, and I can't talk like that. How do you speak to someone like that?

Your sister has control issues. Did something happen where she lost control and was traumatized?

Sounds almost like a martyr complex.

Here is a link about Martyr Complex. that explains it well and what to do about it to help defuse it.

What is a Martyr Complex? 18 Signs to Look Out For in Others ⋆ LonerWolf

If she still wants the car loan, the answer is still no. Its the same as asking you to buy her a car outright, only worse - its not as obvious that she is asking you to go in debt for years.

Have you ever looked into emotional blackmail? It sounds like that is what she does to people. She makes you suffer emotionally if you don't do what she wants. I recommend that you read a bit about it.

P.S. I agree with wise unaluna. Rock solid no on the car.

I am so sorry this is happening to you. I thought perhaps you sister may have undergone some trauma or grew up with an upbringing where she was forced to play the caregiver role to an extreme or even just a personality glitch, but it seems like it may not be so. Unfortunately, you may need to cut ties or set firm boundaries with your sister. You have the ability to take care of yourself. You are capable of taking care of yourself. You do not need your sister to care for you. As for the car, it's illogical to buckle down on a car on the basis someone will die. That's not true. Do not allow your sister to blame you for the death of a love one over financial reasons. Give her a call and be honest. This is not your battle, it is hers and hers alone.

How do you talk to someone like that? You don't. The minute you hear anger and abuse, you can tell her that unless she speaks to you with respect, you will not have a conversation. She will get angry and try to deny her behavior. Ignore it, and hang up. People get angry when you call them on their behavior and have good boundaries. She has problems and issues that you cannot help her with. She won't change unless she recognizes how toxic she is. You wouldn't allow someone to throw rocks at you, and that is what she is doing verbally.

She is behaving like a spoiled child. What do we do will children who have tantrums? We ignore that bad behavior. Take care of yourself. Don't allow her to abuse you and bully you.

You are going to have to set some boundaries no matter how uncomfortable that may be. A good start is saying no. Saying no can sometimes stop people in their tracks. One thing to remember is you do not need to explain why you are saying no. NO is a full sentence. Or if you feel you have to follow that then say "No, I am not comfortable with that". Its up to you if you want to lay out your boundaries ahead of time by having a conversation with her. Sometimes that can be helpful. If you do choose to do that it would be good to vocalize what you will and wont tolerate and include a consequence- like you will end calls if she hollers and cajoles. Or that you will limit your calls with her. But also do not ask for her help with little things. This can give her the message that you invite her demands as an exchange for helping her.

I thought the article I posted the link to gave helpful ways to deal with these behaviors. Sometimes this is learned behavior from a parent too. A person can have this complex not even realizing how unhealthy it is.

It's an educational read and worth reading. And yes, there can be emotional blackmail involved with this complex.

thank you all for advices and the link, I will read it. It does sound like she wants to be a martyr for whatever price. When I didn't want to talk to her, because she was like that, she called literally everyone I know and told them how "unreasonable" am I and that they all need to "talk some sense into me and make me do what she wants". I was so angry I was shaking and I even felt some tightening in my chest. And it gets worse. She convinced our dad, who had a cold, that he has covid (although tests were later proven negative), even when he was just sniffling, coughing a bit and didn't have fever or anything. Mom and me caught the same bug, it's cold. He was fine, laughing, eating, normal, but no... she had to intervene. He had very bad covid case in her mind. She managed to get him some antibiotics "just in case". Those pills ruined his stomach, he is constantly in pain and nausea, and he didn't even need it. Now he is just sleeping whole day, doesn't eat, and says he feels nauseous and his stomach hurts. That is lasting for almost a week. Before that he was fine! Mom and me have a freaking cold! Mom for some time looks like she has some kind of dementia, now there is no one to take care of her. Also, their outside cats were starving. I had to go there to bring food and feed cats. I am so tired. I don't really know this is all her fault but I can't help but to blame her. Why did she meddle into that? She was screaming at me, as always "he is dying, YOU HAVE TO go there and be with them (our parents) , I can't do it all". I was like "I have a job, I have a child, I can't just move there, dad was fine, what happened". then she called everyone else to tell them I am unreasonable and dad will die, and mom needs care and I need to be there every day. I am so tired. So, so tired. We had one parent with disability, now we have two. And he needs a doctor, really needs it! This is insane! I don't think she even realizes how wrong she is. She claims now he has pneumonia. Tells it to everyone. Of course, I need to go there and take care. I had healthy happy dad just a week ago, what happened? MOm and me have the same disease, as we got it from him, it's freaking cold!!! I am not really in panic I will lose both parents before next year. I think she still believes she is helping, but now dad just sleeps and doesn't eat at all. It looks bad. I am scared this will end really badly. Like living in a nightmare. We just needed all to go to doctor. Can side effects from antibiotic kill older person?

I have read the article, yes, it sounds like Martyr complex. It almost completely matches. But I don't have it, and we are sisters, we grew up together, same parents. How did it happen?

It can happen with siblings where one develops it and not the other. Same thing with NPD or other personality disorders.