Getting past the fear of whether bipolar is going to mess up your life is going to be key. It may or it may not. The thing is do you want to delay or drop your dreams due to an illness you may have no control over? If you truly want to do theater or music then go for it. If you don't have a psychiatrist or therapist you should do that so you get meds for stability and coping skills for everyday living. Do everything you can so you can pursue what means the most for you.