So my (17f) sister 25 and I have always been very close we shared a room for the majority of our youth and we've always been more like friends. My sister moved out a year ago, and since then, she's changed she hardly contacts me or my dad or out other siblings and has very much decided to live a life without us. I don't understand why she decided to do this, especially since my family has always been close. It's hard for me to see this effect on my dad he misses her a lot, and she doesn't message or visit us.

My issue with my sister began last week when she asked me if I would like to come to a birthday party she that her friends are holding for her, I agreed and was very excited about it. My sister also came back to stay with us for the Easter break. I haven't gone out at all during the holiday due to exam stress. I'm in year 12, and I have mocks soon. I've been really depressed lately. I used to do really well at gcse, but now I'm struggling with my workload. My friends have also become a little distant lately, and I don't know if I'm imagining things due to my stress. My sister has been teasing me for staying in bed all day and has been really mean. I'm someone who can take a joke but sister has been taking everything too far I'm the butt of every joke and when I told her to stop she made me feel embarrassed by acting like I over reacted.

I reached breaking point when we had a barberque at my neighbours, and she started telling them all about how lazy I am and how even my friends are sick of me. When we were walking back home I told he that she really upset me and she asked me to stop being melodramatic and that if I continue with acting like this she'll be the only one to miss me when I die. She really shocked me with this comment. I think it was incredibly rude and unnecessary. What shocked me more was her audacity she hadn't spoken to me or our other family members in ages, yet she came back acting as if she has the right to be rude and judge me when she hasn't shown that she cares about me at all in recent years.

She only stayed for a week and she left a few days ago and hasn't contacted me since the day she left nor has she apologised for what she did. Due to her actions I decided to not attend her birthday part for her 25th she lives far away and I would rather not have to take a 2 hour train journeys just to be mocked and belittled by her in front of her friends. My mum passed away 4 years ago and she always wanted us to be close and for the period following he death we were my sister was someone I could always rely on so for her to make fun of me after confided in her really hurt me. I feel so guilty for not going to her party I wished her happy birthday and I do have a gift for her but I'm having a bunch of conflicting emotions so, AITAH?