Slit ventricles can have chronic headaches associated with them OR one might have headaches due to over draining (if lying down helps, that could indicate over draining). But the nose bleed thing sounds odd, really odd. Do you have any other possible cold/illness viral or bacterial whatever that is complicating things? If possible, you could get your eyes checked (someone who could check you optic nerve for high pressure in case of some kind of obstruction). Have you seen your imaging, are the ventricles slit? One can have slit ventricles without chronic headaches. What is a common slit ventricle problem is if you have slit ventricles and an obstruction, but it doesn't show a change in your ventricles, i.e. one can have bad pressure/obstructions without enlarged ventricles, imaging is useless for such people so they need to press on doctors to confirm things are ok when it is more than a chronic headache (and docs may assume all headaches are the chronic kind where some patients may assume all headaches are emergencies) - checking optic nerve, shuntogram, shunt tap +/- lumbar puncture, etc - but it can be hit or miss with intermittent obstructions.