Because

I've turned into a mean person
I've started lying to you
I've started to send you mean things
And I won't even try to undo

It's because
I am lost

I've started to stalk you
Tell you things that would hurt you
I've started to call you names
And I will never be able to undo

It's because
I am lost

Lost since the moment I lost you
Lost since the moment I got you
To the point you don't want anything to do with me
Lost since you've been denying me

I've started to become the meanest person alive
I've started to hurt you in all kinds of ways possible
I've started to hate you with my all