Here’s a fun thing you can do if you have panic disorder that’s triggered by strong smells: Decide to use a tiny squirt of that conditioner sample you got in the mail. Sure, it smelled innocuous in the packet, but it actually came from Satan’s fragrant garden of horrifying chemical rot.
First, go completely out of your mind because the smell is on you, on your fricking body. You can’t escape it. Throw open the shower curtain to get some cooler, fresher air to hyperventilate. Give yourself a little pep talk as you try to rinse the horror from your hair. Sacrifice a perfectly good towel to blot away as much of the (extremely stubborn) conditioner that still remains. Wash your hair again with unscented shampoo. Rinse thoroughly, then smell the ends. Panic again. It still reeks. Wash your hair twice more. Have one more minor panic when you see how much hair has fallen out during this procedure. Condition with your shitty-but-blessedly-fragrance-free regular conditioner.
Clean up all the water on the bathroom floor from your initial shower curtain yanking hyperventilation session.
For best results (as in maximum panic), do this with a pre-existing stomach ache somewhere between the hours of 2 and 3 a.m. when you have to get up early the next day.
Try to sleep, but spend the rest of the night wondering whether you should wash your hair just one more time to be safe.