The feeling, "this can't be it", is a very powerful form of prayer. It's the agony of the separated self longing for reunion with wholeness. It's the call of your soul urging you to return to your own path and purpose. It's the force of evolution driving you home. Do not try to deny or override your divine discontent. Heed its call. Knowing "this can't be it" implies that somewhere inside you, you DO know what IS it.
Will you ever run out of creative ideas and expressions? Ha! The more creative ideas you have, the more you will discover. Creativity is a tree with countless branches that never stop blossoming.