Hi the cyst would explain the cause of your headache,  however the fight doesn't end here I would suggest get an MRI Brain done for better look and evaluation of the cyst secondly consult a neurosurgeon with your MRI and CT, he would then suggest you either an open craniotomy fenestration or ventriculoperitoneal shunting. Depending on the size and location either procedures shall be discussed with you however nothing to worry if you are consulting an experienced neurosurgeon.