I do not think your dream is too specific. Your main focus for this will be majoring in Psychology and you can also take sign language classes simultaneously. I believe you would be able to maintain all of these subjects in your normal class load. If your school does not offer the sign language course, there are several programs offered at nights and on weekends. I'd say keep pursuing your passion and dream, it can certainly be achieved! As a final suggestion, confide with your academic adviser on what you'd like to do and they can help mold a path for you.