This may sound strange but I let myself imagine doing it (the ways might vary), and that somehow helps. It calms me down.
Other times when I'm really on the edge, I'm doing other self destructive stuff. Obviously not recommended.
If I can cry that helps. Other activties that require more discipline like writing it out, breathing exercises could help but maybe when one is calmer.
Music.
Something that reminds me of what I like about life...usually something artistic, related with colours
Watching/ reading something painful, so I can feel my pain expressed in a way.
Maybe a lot of these are not 8/10 stuff...

Sorry that your going through this