Twitching on upper right scalp (like being flicked in the head) followed by pass out feeling. Scared its serious. Anxiety induced? Symptom of problem?

See a physician. Anxiety can cause the body to do many different things. Since you feel like passing out and are scared it is serious please see a physician to see if it is serious and needs to be taken care of. If it is anxiety induced then see a therapist to get better coping skills. At least you won't be afraid you could be dying. What an awful thing to live with. You can feel better.