A 27-year-old man presents to the emergency department with a sudden occipital headache that quickly became severe and was accompanied by vomiting. He has no regular medication use or history of recreational substance use. He has been referred to the genetics clinic due to a family history of phaeochromocytoma and kidney tumors. On arrival, he has a decreased Glasgow Coma Scale, reactive pupils, and a rigid neck. His blood pressure is elevated, and he has two cafe-au-lait spots on his trunk. Urine dip shows blood and positive leukocytes, and an ECG shows ST elevation in V1-V4. A CT scan reveals a large high attenuation signal in the left cerebellar hemisphere with surrounding edema and no mass effect. A lumbar puncture shows xanthochromia color and raised red cells. What is the likely unifying diagnosis?