Is Revelation 3:14 saying that Christ was created by God?

Christ is both Not-created AND created.

Using methods of sensus plenior:

Jesus is the light

   Jn 1:4 In him was life; and the life was the light of men. 5 ¶ And the light shineth in darkness; and the darkness comprehended it not.

   Jn 3:19 And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil.

He is self-existent

   1 ¶ In the beginning God created the heaven and the earth.

The word 'Elohim' for 'God' has a pun 'alo khoom' meaning 'not dark'. The 'not dark' or 'the light' existed before creation hidden in God.

And he is created

   Ge 1:3 ¶ And God said, Let there be light: and there was light. Jhn 1:14 And the Word (which is the life and light) was made flesh, and dwelt among us...

Contradictions are riddles In sensus plenior, contradictions speak of different aspects of the same truth. they are riddles. Jesus is the Only begotten Son AND the Unbegotten Only Son.

Christ as the Light represents the Holiness of God:

   Heb 4:15 For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as [we are, yet] without sin.

Since Holiness expresses a separateness, and the Godhead was unified in Love, Holiness waited for creation to be expressed. Immediately after the heavens and the earth were created God declared, "Let there be Light" and His holiness was made manifest.

Therefore we can say that Christ was created, that he is the firstfruits of creation [1] without fear of treading on his divinity.

He is both the Creator and a created man. That is the essence of incarnation.

[1] 1Co 15:23 But every man in his own order: Christ the firstfruits; afterward they that are Christ’s at his coming.