adonai echad perhaps.
Perhaps? Agnosticism is uncomfortable because it is a state of cognitive dissonance. On the one hand, the agnostic insists that only that which passes the test of the agnostic's reason can be valid. On the other, the agnostic refuses to trust the results of reason because the agnostic's reason may be faulty.
One might describe this as letting the perfect be the enemy of the good; a better answer is that the agnostic is caught between pride on the one had and fear on the other.
If, however, you are claiming that you are merely doubtful whether Jesus is part of a Trinity of three aspects of one Lord (adonai echad in traditional Christianity), then the answer is: you are still agnostic. "Paralysis of analysis" is an annoying phrase used by multi-level marketers to shame doubters into investing despite reasonable doubts; I will not insult you by repeating it. Nonetheless, I will point out that the existentialists admitted that solipsism alone is inadequate: a leap of faith is required. A leap to what, they cannot say, and neither can I command you to have faith from my own authority. We may all be invincibly ignorant, but our Creator has imbued us with the need to believe despite our inadequacies. I will pray for you, and I hope this post is helpful, though I have faith that my prayers are more helpful than any posts.