Also, do you use the computer mouse with your right hand? The combination of computer use/practicing may cause such problems as well.
I went Last week with the neurologist, she told me it wasn't related to the brain physiologically. I went with my therapist, he told me That I am through chronic stress. After talking to him, my twitching got lower. But today, my twitching increased after a practice. I am thinking about going again with the therapist if the twitching is not gone at all.
I think you need help from an expert in piano playing more than medical help. Maybe a better teacher too, seems like you are not getting much help from the one you have now...