Rejoicing doesn't ignore the pain. It is not plastic. It is not inhuman. Those "plastic people" that I so despised in high school which said all was well but were torn to a million sheds inside.
But it does hope in God.
And He is big enough. He can handle our doubts, our fears, the fact we just plain loathe the circumstances. He can handle our questions, even if voiced to others would sound so.....profane.
There is a pattern in Psalms.
Expression of who God is.
Reaffirmation of the character of God and His working in our lives.
Try to follow that pattern when coming to Him with your deepest hurts, regrets, frustrations.
He loves you and understands.
And try out Sons of Korah, signing the Psalms. These young men surely will help your hope in God to be renewed.