Disappointment is inevitable. Allow yourself time to feel sad and disappointed when things don't work out the way you planned. While allowing yourself to feel sad, also remember the sadness and disappointment are temporary. Things don't always work out the way you want, and that's okay. Disappointment is part of what it is to live, to be human, but the journey continues.
Growth is gradual and rarely noticeable right away.
Most of what I take at face-value to be truth is likely just a projection, an interpretation of "Reality" clouded by my own set of experiences.