A Lament by Percy Bysshe Shelley
I’ve always liked this poem… so short, yet so despairing…
A Lament
By Percy Bysshe Shelley
O World! O Life! O Time!
On whose last steps I climb,
Trembling at that where I had stood before;
When will return the glory of your prime?
No more—oh, never more!
Out of the day and night
A joy has taken flight:
Fresh spring, and summer, and winter hoar
Move my faint heart with grief, but with delight
No more—oh, never more!

what time of mood is this poem?
I’m not sure what you mean. It was written in 1821 and published posthumously by Mary Shelley in 1824. I don’t know what was going on in Shelley’s life at that time or even if the poem drew from his experiences. I think it’s very desperate and sad.