I don't know what it looks like exactly in the original Greek, but from what I can tell in English, it seems perfectly possible he is saying
"Before Abraham, YHWH"
Yahweh the Father created with Yahweh the Son.
Isaiah 44:24: “Thus says Yahweh, your Redeemer(Jesus), and the one who formed you from the womb, ‘I, Yahweh, am the maker of all things, Stretching out the heavens by Myself And spreading out the earth all alone.”
So the way many Christians(not all) understand this is that everything was made for Jesus by Jesus, but then the scriptures say that Yahweh is the maker of all things.... hopefully you can see that Jesus and the Father are both God and they both created all things. Jesus is the Word and when God created He spoke the creation in existence.... let there be light and there was light... God used His Word(Jesus) to create all things
Colossians 1:16: “For in [the Son] all things were created, both in the heavens and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—
all things have been created through Him and for Him.
John 1:14 And the Word became flesh(Jesus) and dwelt among us, and we have seen his glory, the glory as of the only Son from the Father, full of grace and truth."
Since the Father is God and the Son, you can call them both Yahweh(God) if you really want to... The Hebrew name for Jesus the Son is Yeshua.
The only thing is that God has a Son, a Father and a Holy Spirit.
Hope this helps just a little bit.