When it’s bad, it’s hard to do because those things hurt.
Recognizing that, helps. And helps process things too. But it’s the opposite of pain relief. It’s understanding and working on the cause, which is rarely easy.
It doesn’t sell either, and only self reinforces on the long scale, if one can see it.
Sometimes you know it hurts, but you need to keep going anyway. OP replied to me with the metaphor of physical pain, which works great in this case. If my trapped nerve hurts, I _know_ the root cause of it by now, I don't need it to keep stabbing me in the back for 2-3 weeks while I work on fixing the root cause.
Similarly for mental health, exercise (in particular) provides you with that capacity to handle things. If a person is under serious stress financially, they _know_ they're struggling. If exercising 2-3 times a week can help them keep that stress under control so it doesn't destroy a relationship in the process, that definitely seems like a worthwhile use of time (rather than "feeling" the stress).
If you can't muster the executive function to perform basic tasks, you definitely can't handle the root cause of whatever is pushing you over the edge.