Here "you" is plural and refers to the people of Israel. The phrase "my servant" refers to the nation, as a whole. (See: [[rc://en/ta/man/translate/figs-you]])
In speaking this way, Yahweh is not saying that there was a time before which he did not exist or a time after which he will not exist. He is asserting that he is eternal and that the gods whom the people of other nations worship are not.
Here the word "formed" indicates that Yahweh is speaking of idols that people have made. This can be stated in active form. AT: "None of the gods whom people have formed existed before me" (See: [[rc://en/ta/man/translate/figs-explicit]] and [[rc://en/ta/man/translate/figs-activepassive]])
# there will be none after me
"none of those gods will exist after me"
# I, I am Yahweh
The word "I" is repeated to emphasize the focus on Yahweh. AT: "I alone am Yahweh" or "I myself am Yahweh" (See: [[rc://en/ta/man/translate/figs-doublet]])
# there is no savior but me
This can be expressed positively. AT: "I am the only savior" or "I am the only one who can save you"