Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to examine you and obtain a history, I can not tell you what the exact cause of your symptoms is. However I will try to provide you with some useful information.
In a person with cavernous angiomas, sudden severe headaaches may signal a significant bleed within the angioma, and for sudden severe headache, immediate evaluation in an emergency room is indicated. For headaches that are more chronic and less severe, the cavernous angioma could potentially be causing or contributing to the headache, but other causes of headache such as primary headache disorders (such as tension headaches or migraines) are a possibility as well. It sounds like you have scalp sensitivity; this would be unusual for the angioma to cause unless it is in specific areas of the brain. Discussion of your headaches with your neurologist is recommended as there are often effective therapies for headaches (if the headache is due to the angioma, or otherwise). Avoidance of medications that may cause thinning of the blood would be important to keep in mind.
Cavernous angiomas can cause seizures because the small amounts of blood deposits in them irritate surrounding brain tissue. If seizure medications are not effective in controlling the seizures, and the seizures can be shown to be coming from the area around the angioma, surgical removal of the angioma can sometimes be done. This should only be done in experienced centers.
Evaluation by your neurologist is recommended, and if your seizures are not under good control, evaluation by an epileptologist (a neurologist with specialty in epilepsy) is recommended.
Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.