Christie, that's EXACTLY what it was like for me too. XD It's moments like that where you feel really vulnerable and are scrambling to find a safe place to hide with very little options with like no time to do think things through the game was at it's best. To keep from blacking out, just hang out in the light or with your lantern on for a couple minutes. I only had like once in my entire playthrough where I blacked out from insanity. o.O Did you try to do everything in the dark? It was probably why it started screwing with you.
One of the parts that was like the closet bit you mentioned that deserves an honourable mention is when you stab yourself with the spike drilled in the corpse's head to inoculate yourself from the fungus spores in the sewers and you pass out. When you come to, you head to the door to continue on the way and then a new monster you've never heard before is breaking the door down and there's like no closets to hide in so you have to run to the next room with no door and a shitload of dead bodies and hope it doesn't come in there to look for you.

That was spooky.