How we cite our quotes:
He knows who tries it how cruel is sorrow,
a bitter companion, to the one who has few
concealers of secrets, beloved friends.
Here, the speaker personifies sorrow as a "bitter companion." But the effect of this personification isn't to make the abstract quality seem human; instead, it's to emphasize what a difference there is between sorrow and real, human friends.
Joy has all perished!
So he knows, who must of his lord-friend,
of loved one, lore-sayings long time forego.
The notion that all joy perishes without a lord shows just how important the relationship between lord and nobleman is for an Anglo-Saxon. Not having a lord makes the whole world unbearably miserable, until there's no happiness to be found in it at all.
Then are the heart's wounds ever more heavy,
sore after sweet – sorrow is renewed –
when memory of kin turns through the mind.
Sweet memories of better times do not relieve the exile's sadness. Instead, they make it worse by reminding him again of how much he has lost. Memories and dreams condemn him to a life in which the stroke that caused the initial wound – the separation from loved ones – always returns to wound him again.