Peace, my friend!
The truth is fixed and eternal; the anchor is a supply on the ship, used to fix the ship so that it will not leave its place no matter the wind and waves! It is more appropriate to use an anchor as a metaphor for truth, but this is only a metaphor in appearance.
"The truth and I are like an anchor, anchored in the unfathomable ocean." It means that I am the truth, or that I am a person who upholds the truth, regardless of the worldly errors, ignorant malice, and lustful corruption around me. Attack me, besiege me, and persecute me, but I will never waver!
It is really hard to find such a person in the world. Unless that person knows Jesus and accepts Him as the Savior, he is not a person who can uphold the truth! Because Christians can adhere to the truth because they obey the leadership of the Holy Spirit, which is the manifestation of God’s own power in people!
I sincerely hope that you will become an "anchor of truth" soon. May God bless you, Amen!