Recently i can't think straight, some call it brain fog. i have a constant mild headache and my short term memory has deteriorated. is there something wrong with me?

Perhaps: you should immediately consult with your personal physician and let him/her evaluate your neurological signs and symptoms. Some blood will likely need to be drawn, and perhaps a ct or mri. medications can cause your symptoms.

Causation?: At your age, maybe due to sleep disorder, thyroid, medication, drugs, alcohol, depression, vitamin deficiencies, occult infections. Have your doctor seek out