First of all, with any symptoms of new or recurrent headache with visual changes or confusion you should call your doctor ASAP or go to the ER, because that's the kind of symptoms you would get with rebleeding. So if you're still having the symptoms from the other night, give your doc a call.
A cavernous angioma is an abnormal collection of tiny blood vessels in your brain. It's not a tumor and within the collection of vessels there's no brain tissue intermixed. Cavernous angiomas can bleed (.5-1% risk each year) and then calcify (collect calcium) or cause seizures and other neurological problems depending on where they are. I'm assuming that when you said "optical" you meant occipital lobe which is the back part of your brain that controls vision and is right next to the cerebellum which can causes dizziness if there's a problem there.
Before you go to your next visit, call your docs and tell them your symptoms. Also let them know you'd like more information on what this is and what you can expect. I can understand that a bleed in the brain can certainly be scary, but the more you understand about your condition and what to look for, the better off you'll be. Good luck.