Marianna ~
Hydrocephalus, as you know, is a serious condition and can lead to brain damage. However, if you do not have any symptoms, you can probably wait until Monday but you'll have to have the condition addressed very soon. Just be vigilant of the symptoms that would require a 911 call: headaches, vomiting, nausea, sleepiness. I would take it easy this weekend and stay near a telephone, just in case. 'Freaking out' is understandable here - but not too helpful.
After my AN surgery, the neurosurgeon told me that once they opened up my skull, the CSF literally 'gushed' out of the incision and that my brainstem had been severely impacted. He was quite surprised that I never showed any symptoms of hydrocephalus. I was just grateful. I mention this because you could be in the same situation. Having the condition doesn't necessarily mean it will become an instantaneous problem but I expect your doctor will want it addressed almost immediately. Please follow his advice. I wish you the best and trust this will work out O.K. for you.
Jim