Really struggling with my mood

I was so happy, so damn happy today and now suddenly my damn mind wants to tell me that I’m better off dead. I’ve accepted that I’m going to die very soon, I won’t make it past 25 and it’s okay, but Jesus my mind is so violent. It tells me I’m a fuck up, I disappoint everyone, I’m a burden, I shouldn’t be alive, I’m a mistake. Maybe I am a mistake, idk.