my sister doesn't like me

I'm 24 years old and my sister is 22 years old.

We were very close when we were younger, we used to play a lot and have fun together.

3 years ago my sister was diagnosed with severe depression and she is medicated most of the time. She depends on the pills in order "to feel normal". Last year we got to know it was because she had very low iron, not depression, but sadly she is still dependent on the pills.

The thing is that I fail to understand why she feels so unwell when I'm around her.

As an example, I'm having a call with someone. And I'm speaking in another language, so my tone changes a little bit. She passes by and repeats what I say making fun of my tone and saying it is horrible to listen to that fake voice.

Or we are at a familiar meeting, someone congrats me for some art I made. She interrupts saying that I'm way better at lying.

Last month she had to go with me to a city to get some documents for my university (i needed her signature), and I remember we were at the train in the morning. I tried to talk something with her, talking about the how cold the day was.

And she literally asked me to shut up and that it was a horrible day for her to be in the train with me. I remember that day, I cried the whole afternoon.

I made her a custom birthday party with her favorite cartoons this year. Even made her a cake with her favorite character "pompompurin". Gave her lots of accessories, I wanted to hug her and she pulled me away. She didn't even say thanks.

The interesting part is that she's very mean to me and to my mom. But she transforms into a whole different person when her boyfriend is around. Also when she is with her university friends.

She changes so drastically, that even the tone of her voice changes. When he's present she's super loving, caring and even has lunch with us at the dining room.

Of course I have tried to talk with her many times. She says she sees no issue, basically we can go on without talking in months despite we live in the same house, have each room next to the other, and that's super for her.

Or as an example, she's with my mom watching TV and if I arrive, she says I ruined it and she goes back to her room. She spends most of the time in her room.

It wasn't like that before when we were younger. We used to laugh and share a lot.

I spent 3 months out of the country in Europe, she didn't even care about sending a message, nor responding the ones I sent to her.

One day I couldn't handle the silence anymore. The fact that she's always always wearing big headphones in the house, and when you talk to her she shouts at you "WHAT??".

So I asked her to please have a conversation she said there is no need for a conversation. I started crying a little bit asking her what did I do wrong that she changed so much in a few years towards me.

I remember asking her if she loved me even a little bit. She said no. That I was not nice with her when I was 7 years old, that I used to take some toys away from her (she repeats this a lot when we are in public or in family reunions), and that I was mean and a bully her.

I know I already have the answer to my question, but deep in my heart I don't want to accept that this relationship that was so beautiful died forever.