My mind hates me

Everytime I feel like my mental health is getting better, one small thing can set it all on fire. A couple days ago me and my mum argued, today is my results day and I did worse than I imagined. Everytime something negative happens I start getting intrusive thoughts of shooting myself. Then I keep thinking about it and considering it and it goes on and on and I punch my head to shut it up but it won't shut up. I hate ts