Turn off brain

Seriously, thinking too much is actually a sickness. And what the hell are dreams? I just experienced night four of a disturbing, unsettling recurring dream - just my worst fears realized, no big deal. I hate it I hate it I hate it. Turn off brain! I can at least distract myself during the day, but what can I do at night to stop my brain from focusing on painful things. And then I wake up in a sweat, feeling sick to my stomach wondering if it's ever going to end. And then I can't help but have those words and images in my brain all day long, only to lead to another night of restless sleep. I will be asking God about this whole dream (or nightmare) thing when I die. What's the purpose? Really? I'd like to know...