Moving on

I want you to be happy,
Though I know it is with her.
So I will keep on smiling,
With memories of what we once were.
I will move on though the process be slow.
Because you broke my heart,
And pushed me into a bleak existence
Where it is cold and wet like snow.
Now we slowly drift apart.
With your heart on the mend,
And mine not even around the first bend.
I miss you so much no matter what I say.
But why is it I, for your betrayal, am forced to pay?