When feeling down, it's easy for the mood to appear on your face. This expression, "down in or at the mouth," describes this phenomenon perfectly. However, there are other ways to convey this feeling without saying this exact phrase. For example, you could say "downcast," which means to appear sullen or disappointed. Another synonym could be "dismayed," which implies a feeling of disillusionment or shock. Similarly, you might use "disheartened," which expresses a sense of discouragement or demotivation. Whatever word you choose, just remember that it's important to communicate how you're feeling to others so that they can provide support and comfort.