A singer quotes the words of a song:

You were pretty as a picture
It was all there to see
Then your face caught up with your psychology
With a mouth full of teeth
You ate all your friends
And you broke every heart thinking every heart mends

And then says: Whenever you hear a song where I'm giving out, it's usually myself I'm giving out about. But not in this case.

--- What does he mean by "giving out"?
Maybe revealing. the singer seems to be revealing something of himself. Even though the song seems to be about a woman, maybe he was just revealing his own problems with hurting his friends and breaking hearts. who was the singer?

It's a song by U2.

But at the end he said "But not in this case".

So I understand that he is saying: Whenever you hear a song in which I reveal something it's usually about me, I reveal something about myself, but not in this case.

This is how I see it.