(un)conditional love?

Unconditional love.
Is there really such a thing?
Can we truly be happy just by loving someone,
Even if we get nothing in return?
I used to be happy with just loving that certain person,
Making him happy,
Seeing him smile.
His joy was total bliss to me,
Its like i functioned from knowing he was happy.
But i guess times have changed.
Back then, i didn't mind getting nothing in return,
But now it pains me ever so much.
Watching him smile,
Watching him be happy...
With someone else.
I'm no longer the source of his happiness.
But isn't unconditional love still meant to stand?
Even though i'm not the one to bless his life with laughter,
He is still happy because he has someone else.
Shouldn't i just be happy knowing he's happy?
It's not like i stopped loving him or anything.
So why aren't i satisfied with just that?
I want this feeling to go away,
To disappear.
This horrible feeling of not being needed,
Unwanted,
Unacknowledged,
Unloved.
I suppose i just have to live with it.
There's nothing i can do about it,
His heart chose what it wanted,
So i guess i must respect that.
Even though my smile has died,
I hope he continues to be happy.
In a way,
I guess some things don't change...