Struggling with a Friend's Behavior Triggering Past Trauma

As a child I dealt with being sexually abused, things didn't click until adult hood. I didn't realize what it was until 5 years ago. My little cousin (21) knows about this. We used to be really close but she has become a huge pothead in the last month and is always out of it and also disassociated. She is moving tomorrow. I have been so depressed and suicidal that I was thinking about hospitalizing myself... And just now she messaged me some weird stuff and then a video of herself doing oral on somebody... And then I said I think you sent me something by accident and she said "does it bother you that I sent that?" And I was like wtf yes. Then she said she didn't mean to and she won't do it again... But the way the conversation was I feel like she did it on purpose... And she knew what I went through. Now I have another secret to burden. That her dad molested me as a child, and that she showed me a video of herself engaged in a sexual act. I hate my life so much why would she do that. I love her and we were really good friends how could she think that was okay. I want to tell my mom. And my urges are so high. I'm glad she's moving tomorrow.