Here are thirteen sad short sentences that have a youthful tone in English:

1、In the darkness of night, my heart feels like a lonely planet, orbiting alone through the universe.

2、Despite being surrounded by people, I feel like I am floating in an empty sea of sadness.

3、Sometimes, the memories that hurt the most are the ones we can't seem to forget.

4、The raindrops on my face remind me of the tears I've cried for a lost dream.

5、In the midst of my youth, I feel as if I'm walking through a forest of sadness.

6、The world may be full of colors, but my world is gray, filled with the weight of my sadness.

7、As I look back on my life, I see a path filled with broken promises and unfulfilled dreams.

8、I miss the simple days when we were young and carefree, before life became so complex and sad.

9、The pain of losing someone special is like a scar that won't fade, even as we grow older and mature.

10、There's nothing like the sting of betrayal when someone who says they care hurts your heart by your words unguardedly.

11、My heart is broken like a mirror shattered on the floor, with every shard of glass reflecting my sadness.

12、As I stand alone in the rain, I feel as if my life is a sad poem without a happy ending.

13、Sometimes, all I want is a hug from someone who understands the depth of my pain and sadness.

Each of these sentences carries a weight of emotional sadness that resonates with youthful feelings of loss and pain.