What words are these have fall'n from me? Can calm despair and wild unrest Be tenants of a single breast, Or sorrow such a changeling be?
Or doth she only seem to take The touch of change in calm or storm; But knows no more of transient form In her deep self, than some dead lake
That holds the shadow of a lark Hung in the shadow of a heaven? Or has the shock, so harshly given, Confused me like the unhappy bark
That strikes by night a craggy shelf, And staggers blindly ere she sink? And stunn'd me from my power to think And all my knowledge of myself;
And made me that delirious man Whose fancy fuses old and new, And flashes into false and true, And mingles all without a plan?
Tennyson himself notices the contrast between his previous "calm despair" and current "wild unrest." He expresses some discomfort with both of these existing in the same person, and describes sorrow (previously personified) as a "changeling" (check out "Allusions" for more info on that).
This whole canto is a balance of opposites held in tension: calm and storm; old and new; false and true.
And there's lots of emphasis on things being unstable or transient.
In fact, he seems pretty freaked out by things not being in their rightful place—things "mingl[ing] without a plan."