I am having serious problems with my sister. Almost 4 years ago, I moved away from home and now live 2 states away. I'm 29 and she is 27. She lives at home with our mom but she has a full-time job as a nurse. She says all the time she feels "obligated" to keep living at home with Mom because she is 71 and needs help around the house. Our dad died 8 years ago. Also, we are both adopted and not biologically related, but we have been raised together since her birth.

My sister is a very difficult person to get along with. She is a very, very angry young woman. I believe this stems from her obesity which she has struggled with her entire life. I do not believe she is physically dangerous, though. She used to have electric temper tantrums as a little kid, and my parents took her to a child psychologist to be evaluated. As luck would have it, she threw a fit in the office, the veins popped out of her neck and she banged her head on the doctor's desk. He told them he had no idea on what to do.

We have locked horns a lot over the years. Our personalities are like night and day. I am chronically shy, gentle, somewhat easygoing, and apprehensive. She is fiercely independent, somewhat arrogant, gregarious, and jealous. You really have to tread on eggshells around her because if any little thing you say bothers her, she will take it as a personal attack even when nothing of the sort was ever attended ["What do you mean by that?" "Why are you doing this?"] and get full-blown angry over the slightest thing, which I will explain later. We have been able to keep peace in the valley by spending limited amounts of time with each other. She has a great sense of humor and we would frequently go to the movies when I was home visiting, or look up funny stuff on YouTube.

However, over the past 6 months or so, our delicate arrangement has disintegrated as well. She is irrationally jealous of me. She always calls me "the favorite daughter" to both me and our mom. I believe she really resents me for moving away, you know, I "escaped". Our relationship really came to blows 3 months ago over the stupidest thing. I was home for a friend's wedding, which I went to with my mom. She came home after us. She was steaming because I apparently parked in "her spot" in the driveway, her exact words were "Why did you F-ing park your F-ing car in my spot???" She angrily yelled this phrase. I told her "F you, first of all Mom drove because I was drinking at the wedding, and secondly can't you see it's pouring down rain and we didn't want to walk very far to the house?" She launched into a tirade and slammed a door, which caused a picture to fall off the wall and break. We haven't had a meaningful exchange nor a full conversation since that night. I am not apologizing to her, because she needs to learn that she will not get her way with this disgraceful and immature behavior.

I think the best thing for all of us right now would be for her to move out of the house, but she wants to keep playing the martyr saying she has to do all of the work helping out our Mom. My mom has brought this up, saying "I really think it would be better if we went our separate ways" but she will have none of it. I really wish my mom would just kick her out. She does help my mom out a lot financially, though. I wouldn't mind coming home more often to help our mom out, because that's what families do.

I erroneously thought she would be a little better by the time the holidays rolled around because I thought she would lighten up with the passing of time. I've only been home for 24 hours and it's been absolutely miserable around here. I haven't been able to escape all day because of the holiday. She was so snippy and disdainful of us the whole night. While I still love her because she is my sister, the rest of my feelings for her have turned into contempt at this point. I see a therapist because of my own issues (not relating to the family) and I do bring up my relationship with her from time to time, so I am talking about it. But it's hard to tell anyone else about this, though, because most of my friends and all of my family obviously know my sister and I don't want to make her look bad. That sounds kind of silly, because she has no problem making my mother and I feel like fools all the time. I feel like although we don't all live together anymore, we are emotionally not a family either. When I do come home to visit, she is either at work or sits upstairs all day. We don't even sit down to eat together or watch TV. It's just a completely horrid situation, it's really depressing me and getting me down, and that's unfortunate because I have been recently making a lot of progress in my own therapy. I feel like it's ruining the work I am doing and I am trying my best to not let her get the better of me. I am trying to stay positive and am looking for things to do while I am here (going to see friends etc.) but it's just so hard. I just hate her guts right now.