Could violently snappin my head back and forth to style my hair all my life cause head trauma or cause my brain fog/head sensations/confusion? i'm 19

No: The movements would have to very violent and rapid to cause any neurologic damage. Make sure your doctors rule out sleep apnea as a cause of your symptoms you list above, as this is frequently missed in young people. At the very least, a home o2 desaturation test should be run to rule this possibility out, followed by a home or lab sleep study if clinically indicated.I hope other docs chime in als.