I (19F) am so fixated on ruining one of my ex best friends life. I've been obsessed with this idea for around 5 days, but it's been building up for probably 3 weeks now. I RARELY do this now. I used to think this way a lot back when I was younger but since being in therapy for 5 years I've matured a lot more and have a better understanding of wrong and right. However, I have tried to shake this idea off and I cant. It's to the point where I've came up with a plan to make a fake email, and contact her work.

You can stop there if you'd like, but I'll add a childish petty backstory just in case anyone cares. 

It started with her self diagnosing herself as bipolar. She's recently gained a lot of tik tok followers for expressing her mental health issues and becoming an "advocate" for it. Most of her videos consisted of her saying she has BPD because she thought BPD stood for bipolar (I fucking hate that). We got into an argument and she realized she was in the wrong so she took it to tik tok to seek validation from her followers. I saw the video that was made about me and commented that she self diagnoses herself and that she's fucking delusional. She responded back to my comment saying that she was in fact diagnosed as bipolar, but is now educating herself on the difference between BPD and Bipolar disorder. I left it at that but then mutuals contacted me and sent me her new videos. She had deleted her video where she claimed to be diagnosed as bipolar and has now turned her whole social media feed into videos about her BPD struggles. She posts the typical webmd keywords about bpd and constantly goes on and on about her "borderline derealization" and "borderline struggles".

As of today she's also claiming to have autism.

I realize this is all so childish but I seriously just cant brush it off at all. I hate that she self diagnoses for followers and validation. I hate that I want to do this so badly but everything is telling me to. I don't know a healthy way to cope with these intrusive thoughts! I feel so disappointed in myself but if I don't get a response I'll probably end up doing it. It also doesn't help that I expressed this to two of my other mutual friends with her (my closest ones) and they agree that I should do it.

TLDR: Ex best friend self diagnoses herself with many disorders, makes tik tok videos about her "diagnoses" for validation from many of her followers. I'm struggling with intrusive thoughts and am extremely fixated on messaging her work pretending to be someone else and sending them her videos/making up reasons that they should fire her. I feel manipulative and ugly but I don't think I can stop.