I dont seems to understand what is love ?

To me falling in love is awfully simple but falling out of love is simply awful
We think about it, Sing about it, dream about it , loose sleep worrying about it.
When we don't know we have it, we search for it.
When we discover it, we don't know what to do with it.
When we have it, we fear of loosing it. I
It is the constant source of pleasure and pain.
But we don't know which it will be from one moment to the next.
It is a short word, easy to spell, difficult to define and impossible to live without.
Sometimes your nearness takes my breath away;
and all the things I want to say can find no voice.
Then, in silence, I can only hope my eyes will speak my heart.
Is this called love or crush?