Burning the natural ingredients is a fine way to release what you’ve trapped. A lot of people have a misconception about what energy is in witchcraft. Inherently, energy cannot be positive or negative. It just is. What’s different is how that energy is charged. In this case, the energy contains remnants of nightmares, trapped worries and stresses, and general everyday anxieties that the mind holds on to at night. When you burn the ingredients, you’re cleansing that energetic signature and removing the influences that are on it, giving it permission to go back out into the universe in a neutral state.
I’m not sure what the ingredients you used were, but obviously, we want to make sure what you’re burning is safe to burn and that it’s done so in a safe manner..
Alternatively, you can always dispose of spell remnants in the trash, but I would leave that as a last resort. That’s just my own practice and belief.