What does the ending of "Could Have" by Szymborska mean?

The line about being on the right and left makes it seem like a political expression, like a rebellion, and the speaker is confused or is being confused about what side he's on, the left or right. The heart pounding inside of the speaker is maybe part of the political movement/rebellion, which, as they usually do, tries to consolidate people with mottoes of solidarity in order to keep the struggle going,