Make not your rosary of yew-berries, (5)
Yew-berries are another poison that we should reject. There are a lot of drugs, herbs, poisons, and wines packed into the opening lines of this poem, and the speaker tells us forcefully to reject them all.
For shade to shade will come too drowsily, And drown the wakeful anguish of the soul. (9-10)
This is where the speaker tells us why we should reject all those drugs and poisons: it's because they will make us numb and "drowsy," and we should be awake and alert, even in our anguish.