The Truth Comes After the But

I watched Dr. Phil too much. He always says the truth comes after the but.

The Truth Comes After the But

When I walked away you said you would always love me
But time has proved those were only empty words.

I believed those words
But now I find you no longer care.

You see it wasn't that I didn't love you, I did
But I did not want to grow old and look back on what might have been and I believed our love would endure until our last breath
But time has made you bitter and me lonely.

When did but become our unspoken truth?