I believe in the Trinity. The Bible refers to the 'Godhead' multiple times (Godhead is a plural term), and 1 John 5:7 says, "For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one."
And here's an interesting link on the controversy of that verse: https://www.chick.com/ask/articles/1john57.asp
OK. I had been wondering what your specific belief framework is, and this information helps. Mormons are often relegated by Trinity believers to being "non-Christian" because of the fundamental difference in belief about how Jesus fits in with Jehovah, The Father, and The Holy Spirit. A difference of opinion on those details was no barrier to Christians for four centuries until the Nicene creed defined it your way. Christ never taught the Trinity, and it is nowhere in the Bible. As I understand it, the term does not appear in Christian literature until after the fourth century C.E. . But it is what both the Orthodox and Roman Catholics believed after that, and what the Protestants took along with them when they broke off.
I don't think I can really change your thinking, but I wouldn't say you're not a "Christian" for believing that way. Whatever the reality of "God" might be, we are here just talking about how we understand that. I don't think it changes the way "God" deals with us, exactly. It does change the way we interpret a lot of things.
A more important item to discuss might be the difference between what the Israelites believed Jehovah to be and what they believed their Messiah would be. Try that out in Psalm 110, the first verses, which has YHVH or Jehovah as distinct from the Messiah, David's "Lord", who would sit on the right hand of God. Pretty much takes two persons with different corporeal existence for one to sit on the side of the other, just like in the New Testament where one spoke from Heaven while the other was standing in the water after being baptized.