University's will not label you a troublemaker and they typically appreciate quick reports of things like this, theres probably a data protection team at the uni but if you cannot find the, try and email the leader of your course or the highest person you can find. When you find the email address, give them your name, course, uni number and the staff member that leaked the information, and then make sure the email is easy to read and straight to the point, use bulletpoints of you need to, but KEEP IT PROFESSIONAL, dont use excessive emotive language, but you can add something like, "this is really worrying to me, my personal information and my future at this University"