It's usually easier to change ourselves and our habitual responses than it is to change other people. You could say, "I need to take a five-minute walk." Then do it.
Let me say it like this. If it wasn't a socio-emotional thing, but physical pain, there shouldn't be an issue. I see a friend hammering a nail into their hand all the while going 'My hand hurts.' Do I just say 'I don't want to see the blood and pain you're going through so I'll remove myself from the situation' or do I say 'Maybe stop hammering that nail into your hand.' Why is someone making themselves feel worse about something not the same?
In both cases you want to help. In both cases, you want to stop the pain and damage. Yet, in one case you can pull away the hammer and mop up the blood. In the other case you have to talk to a person who cannot or will not see your point. If verbally trying to help a person get beyond something they are obsessing about is not working and is hurting both you and the other person, it might be an idea to try something else.
Like get out of the car? I'm loathe to just change topics and 'leave something until later' because I come from a family where 'We'll take care of it later' means 'We'll take care of it never.' I want to address a problem when I see it, so the solution has context, rather than in some abstract way that never actually effects change.it might be an idea to try something else.