No reason

A sudden wave of darkness has settled over me, leaving me feeling alone and frightened. I know there isn't a reason for it yet I can't shake it. I try and will it away yet it rushes back stronger than before. Every time it hits me its like I've never felt it before. It shocks my system, I find it hard to breath, I find it hard to maintain my composure. I don't know what to do to make it go away. I don't know how to stop it from coming back. I try to find a cause, a reason, anything that would explain this, yet the harder I look the darker it becomes.