i read my sisters diary

ADVICE PLEASE ... my sister and i have been rebuilding our relationship for the past 6 years after an intense childhood of being put against each other. she was a constant bully to me, and i was the younger sister who ratted her out on personal things. that being said, the past couple years have been interesting as i am the one to constantly pursue making our relationship deeper? i initate hangouts, plan times to talk, etc and am often asking for her attention. i have been completely transparent with her in how i feel and recently had a conversation about how i wanted more intention and transparency with her and asking for more grace when i mess up because she is quick to cut me with words. she is also very aggressive with me, and verbally abusive - where i have to sit her down and walk with her through her feelings every time. she told me specifically to not read her diary and that made me want to. i know it is completely awful and wrong of myself and i know i am never going to do this again. but i am stuck, do i tell her i did it or no. because what i read also broke me so much. she had written that she was tired of me being her sister on my birthday, along with other things. im not sure where our relationship is now and i have more perspective on just how much she is masking with me. i love her so deeply and i am extremely pained at how she thinks about me. i know i was not meant to see this and i should have not - point blank period. this was entirely wrong of me to do but i do not know what to now. the entirety of our relationship is more nuanced than this singular post, but i have never felt this misery before, and she has written that she constanltly does. what also upsets me is that i have asked her multiple times before if there is something i can do to be better, or what she needs of me, but to this, she says she does not.