What is Love?

As I was reading the psychoanalytic view of The Great Gatsby, I stumbled upon an intriguing quote:

"..romantic love is the stage on which all of our unresolved psychological conflicts are dramatized.." 

This made me think deeply about what love truly is, which forces me to ask:

Is there such thing as love, or do we only love what we psychologically need based on our past?

I know that in The Great Gatsby, each relationship had their own problems, and it was because of the fact that they were merely using each other for their own benefits, which ultimately related to how they were raised.

But let's face it: The Great Gatsby is not the best book to rely on for love advice.

If love were solely based on psychology, then why is it possible for two people to care more about each other than themselves? It takes two to love, and it would be extremely invalid to say that every single relationship in this world consists of two people who are only drawn to one another because one contains the psychological needs of the other... everyone getting struck by lightning is more likely than this being true.

And love isn't only an emotion you have toward someone, but it is composed of many emotions that two people feel for each other; it has to be felt by both in the relationship. Love combines two people into one, creating a brand new human being.

Love DOES exist, but it's one of those things that is rare to find and hold onto; but when you find it, your whole world will light up and you will know, deep down, that you're in love.