Certainly, here are some sad quotes:
1. "The worst kind of sad is not being able to explain why."
2. "Tears are words the heart can't express."
3. "It's sad when someone you know becomes someone you knew."
4. "Behind every beautiful smile, there is some pain that you can never see."
5. "Sometimes, you have to be your own hero, because sometimes the people you can't live without can live without you."
6. "Sadness flies away on the wings of time."
7. "The pain of yesterday is the strength of today."
8. "It's hard to forget someone who gave you so much to remember."
9. "The scars you can't see are the hardest to heal."
10. "Sadness is but a wall between two gardens."
Remember, while it's okay to acknowledge and express sadness, it's important to seek support and reach out to friends, family, or a mental health professional if you're struggling with overwhelming feelings of sadness or depression.