Lines 17-31 Summary

Get out the microscope, because we’re going through this poem line-by-line.

Oh, I have made myself a tribe
out of my true affections,
and my tribe is scattered!

Now, the speaker is brimming with emotion while he remembers past attachments, loves, and lives that are no longer present.
These memories are sure getting a rise out of the speaker and Kunitz makes that clear, ending line 19 marked with an exclamation (!).
At first glance, these lines contain some peculiar words, like "tribe" and "affections." A "tribe" is a group of people, plants or things that share a common tie. "Affections" are forms of attachment or influential bonds we may have to a person, thing, or event (like to our moms, our cars, or our favorite holiday).
In this case, the speaker recalls previous connections that influenced him in a meaningful way. These bonds (or "true affections") are abundant and "scattered" across many places and time periods.

How shall the heart be reconciled
to its feast of losses?

The speaker is overcome by his feelings at this point, questioning how he can move beyond his previous attachments and hardships.
After being hit by a strong wave of emotional loss, the speaker struggles to "be reconciled"—to accept or come to terms with heartaches from the past in order to persevere.
This is a pivotal moment in the poem where the speaker asks himself a tough (and rhetorical) question. He must decide whether he wants to dwell on the trials and tribulations that have already taken place, or move forward and grow wiser from those tumultuous (super-dramatic) experiences.

In a rising wind
the manic dust of my friends,
those who fell along the way,
bitterly stings my face.

Before answering the question from the previous passage, the speaker reflects on old friends who were swept up by the hardships that life entails, unable to continue their journeys. These memories pelt the speaker metaphorically, like a "manic" (frenzied or agitated) "dust" storm.
The mood is mournful here and the emotionally disheartened speaker grapples with choosing the same fate has his fallen comrades or attempting to move beyond the fray, even if his memories are hard to bear.

Yet I turn, I turn,
exulting somewhat,
with my will intact to go
wherever I need to go,

The biggest transition of the poem takes place in these lines with the speaker choosing to "turn" away from painful memories.
He regains forward momentum with a renewed outlook on what the future holds.
In line 26, the repetition of the verb, "turn," demonstrates change occurring and of a new lifecycle beginning. (Kunitz really likes this cyclical nature stuff. See the "Symbols: Turning" section and "Sound Check" for more details.)
In addition, a positive upswing of emotions is indicated in line 27 with the verb "exulting" (to be elated, joyful, or triumphant).

and every stone on the road
precious to me.

Now that the speaker is in his "happy place," he sees all that transpired in his life (the good, the bad, the ugly, the really ugly) as learning experiences.
In line 30, Kunitz chooses to use "road" explicitly, though he's been hinting at the speaker traveling on an internal journey all along.
Instead of mourning the past, he's embracing "every stone" as a "precious" (or cherished) opportunity that has allowed him to grow stronger and wiser as a person. (This is also why wizards have cool beards.)
We're also seeing an image pattern emerging. (See the "Symbols: Stones" section for more.)