If it must be so

If my heart has to suffer
So that yours may move on
I'll have to be much tougher
And accept the fact you're gone
I didn't want to give up
Because Marines don't ever fail
But to that title I can't live up
For I have tried to no avail
I could say that I love you
Even though you know
But if I love as I say I do
I have to let you go
So this is my goodbye to you
The one I came to love
May the next one love you like I do
Cause you're a gift from above