The most unpleasant feeling is the feeling of your helplessness.

To weep is to make less the depth of grief.

[…] Give me your tired, your poor,
Your huddled masses yearning to breathe free,
The wretched refuse of your teeming shores.

Negative emotions like loneliness, envy, and guilt have an important role to play in a happy life; they’re big, flashing signs that something needs to change.

He was my North, my South, my East and West,
My working week and my Sunday rest,
My noon, my midnight, my talk, my song;
I thought that love would last for ever: I was wrong.

The stars are not wanted now: put out every one;
Pack up the moon and dismantle the sun;
Pour away the ocean and sweep up the wood.
For nothing now can ever come to any good.

W.H. Auden, Song IX, 1976.