You left me for her?

What happened to us?
I thought you were the one
You held me tightly
And kissed me gently
I thought you were the one
I thought you loved me
I thought you cared
I guess I was wrong by far
You left me standing in the dust
All alone
And nowhere to go
I had no money
I had no home
You were the only thing i had
I left everything behind
Just to be with you
I thought it was us forever
If I had known
I would've never gone
For now I have nowhere to go
I would go back to you
But I might find HER there
And I wouldn't want to stop the fun