I'm not sure why it stopped working. It probably worked for maybe 2 years or so. From what I hear people can build tolerance for the anti-convulsant effect of the drug but I am not sure if that is why it would lessen the tinnitus. I haven't tried Xanax since because I thought it was benzo drug too and it might not work either. Would another anti-convulsant drug work for me? Has anyone else built up a tolerance to a benzo and then tried something else and it worked?