Lethargy.

I am tired.
I want to close my eyes, go to sleep and mean it.

I'm beat.
I wish I could make the world stop turning for a moment so I can take a break without the guilt feeling of slacking off.

I'm fagged.
I wish to escape from the role i am currently required to play.

I'm exhausted.
Please stop.

I'm over fatigued.
Somebody save me.