@Thea_Child_Of_Athena got that one first. It was Fireflies by Owl City.

The next one is,

Don't try to explain your mind
I know what's happening here
One minute, it's love
And, suddenly, it's like a ___________One word turns into a war
Why is it the smallest things that tear us down
My world's nothing when you're gone
I'm out here without a shield, can't go back, now Both hands tied behind my back for nothing, oh no
These times when we climb so fast to fall, again
Why we gotta fall for it, now I never meant to start a war
You know, I never wanna hurt you
Don't even know we're fighting for
Why does love always feel like a ___________