There is no quote that describes sadness but there are lots of quotes that describe pain.

I am not upset that you lied to me, I am upset that from now on I cannot believe you.

If someone is bullying you, stand up because you are strong,

If someone you love hurts you cry a river, build a bridge, and get over it.

When I am crying and someone hugs me, it makes me cry even more.

No one will ever understand how much it hurts.

Sad is a word to express how misplaced we are in this world.

Sometimes silence is so much better than talking, at least it doesn’t hurt.

I did not know how much I loved him. Until the doctors took him away.

Better a poor horse than no horse at all.

The alone may be lonely but at least they have no one to lose.

If it is not a happy ending it will not end.

One travels more usefully when alone, because he reflects more.

Life is only a long and bitter suicide, and faith alone can transform this suicide into a sacrifice.

The lonely become either thoughtful or empty.

Try not to cry since it's finished, smile because it happened.

To live alone is the fate of all great souls.

My silence is another word for my PAIN.

I only go out to get me a fresh appetite for being alone.