Then there's the practical aspect of moving forward and continuing to pursue your most fulfilling life. You're in a place that you never expected to be. You might be older and more vulnerable than in the past, realizing that you need to be open to life and new possibilities, and that you have to learn new ways of doing so.
Obviously there's much more. But Epicurus has provided a framework, if not a path, to continue to pursue your best life. His opponents, in their glib talk of manliness and strength. Have completely missed the point.
You make a good point how #grief of a loved one can put us in unfamiliar territory. There's a profound parallel between your observation about unexpected places in grief and the story about being in Oz.
When Dorothy landed in Oz, everything was unfamiliar - the landscape, the rules, even the very nature of reality had shifted. I think this is similar to the disorienting experience of grief of a close loved one. Grief is perhaps the ultimate Oz experience. You wake up in an emotional landscape you never chose to visit, where all the old certainties are gone.
As you said, we have to be "open to life and new possibilities." Through studies of the Epicurean framework, those experiencing grief can discover inner resources and support systems they hadn't recognized before.