Riddles

My chest starts to cave in on my heart.
That's what it'll take first.
My soul is detaching from my body.
That's what it'll captivate next.
My whole life is full of riddles.
That's what it tells me.
My mind can't understand what's happening.
That's the first riddle: what's happening to me?
My emotions are being manipulated so the riddles are harder.
That's what hurts: feeling depressed for no reason; that's the second riddle.
My mind scrambles to hold on to the "it" that speaks of riddles.

I guess that's the main riddle: what is "it"?