Short version: Last year, The Work as taught in Loving What Is by Byron Katie gave me perspective and tools that enabled me to function professionally and personally through/despite deep emotional pain/fear/grief--and be open and generous with the person close to me whose life choices were generating the pain while standing firm in my own choices. (Katie would say, I had thoughts about this person's life choices that generated the pain.)

I had already and pretty recently attended almost a full course of CBT skills classes (accompanying a person for whom they were prescribed), which I had found mostly to include codified, acronym-ized versions of techniques I had already been taught growing up or had independently discovered.

I thought the CBT stuff was pretty good, and it was helpful for the person I was accompanying, but it wasn't enough for me to deal with the pain last year.

Katie teaches that you don't have to convince yourself that your original belief was wrong. Often you do find that it's wrong, but often you just find that you're not sure. Once you've achieved some epistemic humility (I might not really know this), the third and fourth questions give you a different perspective, looking at the consequences of holding on to this belief (which I just realized I'm not so sure about) and letting you imagine a world where you weren't being hurt by the belief. You don't try to convince yourself not to hold the belief: you just do The Work and let your mind do its thing.

She includes lots of example dialogs where she plows straight in to hard cases, too. It's worth a read, especially if there's anything you're having a hard time coping with.