Am I in the wrong??

We have grown apart, but she abuses me quiet often because I don’t see her much. I have mental health issues, I’ve made her aware. She has a 1 year old ( bridie) with her partner and I’m engaged. She got mad at me for not telling her right away about the engagement. I told her 2 hours later. She gets mad at me all the damn time and I’m so sick of it. I’m literally not doing anything. I’ve never caller myself her child’s Aunty. Not even once. She called me that, and I’m not the type of person to go off back at someone. So I cleared our nicknames “ unbiological sister” not my choice of nickname. She’s 21 and I’m 19 but she acts like a child constantly. She’s not mature. She got mad at me because I said I wasn’t having kids at my engagement party. Am I in the right to cut her off? This will hurt. But I don’t know what I’m suppose to do when I’m always getting messages like this. This is just a small few of them.