Not a diagnosis, but sounds like depression.
Perhaps counter intuitively, exercise (get that heart rate up and sweat exercise) has always been the most effective for me. Managed my depression for ~25 years that way, such that I only have occasional (temporary) bouts of ennui.
I’d keep up with the touching grass too.
Hope the investigation is able to uncover what happened so other facilities (and this one, assuming it is restored) can prevent another event like this.
That said… what are the chances there were already sufficient preventative measures available and they were misapplied or simply not done?