I hear you. I hear the frustration you are feeling. Let's take things one step at a time.
It sounds like you maybe committed plagiarism accidentally and, for whatever reason, your communication with your professor about that spiraled into mutual miscommunication. Read you school's plagiarism policy carefully. Usually, there is a procedure that professors are supposed to follow if they suspect plagiarism. If your professor didn't follow that policy, you can follow your school's procedure for grieving (or protesting) a grade. If your professor did follow that policy, you should have the opportunity to present your case before an unbiased panel. (I don't know your school's specific policy, but that's probably how it goes.)
In the meantime, you need to write your appeal. Keep it simple and clean. Confess what you did here: That you went astray and neglected your studies due to too much social activity for some time. Say what you have done to get and stay sober. Talk about your sincere wish to go into computer forensics and your determination to do whatever you must to achieve that aim.
As for art and music courses, the goal of a four-year college (rather than a trade school) is to turn out well-rounded, educated citizens who can not only do their selected jobs but also participate fully in the civic and cultural lives of their communities. Hence, every student must take introductory level courses in lots of different subjects. In the long run, knowing something about art and music, for example, will not only increase your enjoyment of the arts but will also allow you to converse more easily with other college graduates in professional or semi-professional settings, such as a social event sponsored by your employer.
Another benefit of being forced to take courses outside of your narrow field of interest is that most young people don't know enough about all of the fields of endeavor out there to know for sure when starting school what they will want to do or what they will be best suited to do for their whole lives. Some students come in thinking vaguely of accounting or forensics and then, in the midst of a course they wouldn't have taken if they hadn't been forced to do so, discover a true talent and passion for anthropology or finance. Required courses introduce you to the wider world. See them as opportunities rather than burdens and you will get the most out of them.
Simone, EssayForum.com