The (passive) "conflict" (as if within himself) is a Greek (active) word "fight" or "race" or "struggle" as used for athletic contests. The ancient Greek word "ἀγωνία" ≈ "competition, struggle" and is the source of the English word "agony".

In the past, one could "see" Paul persecuting the church. Now, one can "hear" Paul preaching the truth. This distinction is reemphasized later in Philippians. The Greek word for "hearing" assumes understanding of what is heard.

The Greek mathematician Euclid formalized the field of geometry where the angle is a fundamental part of geometry. Many students have had to learn geometry and proofs, etc., though some treat it as "agony".

In Greek, the usual prefix to negate the word for "angle" would be the word for "agony". The words are not related, but a play on words or pun is possible.

Might Paul have used such a play on words in his writings?

More: An opposite angle on the agony of punishment