Why do i feel so sad?

Friends we've been for so long
Now true colors are showing
Makes me wanna cry oh yes it does
Cuz I had to say goodbye

By now I should know
That in time things would change
So it shouldn't be so bad
So why do I feel so sad

How can I adjust
To the way that things are going
It's killing me slowly
Oh I just want it to be how it used to be

Cuz I wish that I could stay
But in time things must change
So it shouldn't be so bad
So why do I feel so sad

You cannot hide the way you feel inside I realize
Your actions speak much louder than words
So tell me why