Is Torah separate from God or is Torah actually God? I heard someone say that the Tanya writes that the Torah is a manifestation of God's will and therefore is God. But that seems a little confusing to me. I thought the Torah is just a channel to reach God and spirituality. But then again there is a chazal that says "Oraysa veKudsha Brich Hu chad Hu." What does that mean?

The Zohar which you partially quoted is actually the Kabbalistic answer to your question, but to be accurate, you only quoted two thirds of the statement, and the final third is what clarifies it all. It is written there: "the Torah, God and Israel are one" (note, not: One)(Zohar iii, 73a). The Torah is like Israel, which are both God's chief manifestations and the way He most clearly appears to the world, as well as the channel to reach God and spirituality. This includes God's mass revelation at the Torah-giving to Israel at Mt. Sinai, and subsequently through the prophets of Israel and the miracles He did for us, the Torah & mitzvot and moral/idealistic example of the Jewish people, and the eternal history of Israel throughout the generations. This is true until this very day, including His fulfilling the ancient prophecies through His modern gathering of the Jewish exiles and revival of the State, Land, army and language of Israel, as well as the Torah which we study and follow, which is all how He reveals Himself and His will. Technically, the Zohar says that the Torah, God and Israel are one, but it clearly isn't meant to be taken literally that Israel & the Torah are God (for both Israel and the Torah are measurable and seen), but rather they are how He appears to the world. I'm not familiar with the quote you are referring to in Tanya, but I have no doubt that's what it means.