You should contact the public attorney and have them represent you. It sounds like there is an explanation and the judge should be understandable.
As usual I am in agreement with Attorney Keller. You need to be in contact with the Public Defender's Office in Philadelphia County to receive the legal representation that you obviously need. Good luck.
I too agree with Mr. Keller. Contact the public defender's office. If it is a requirement of your probation that you attend school regularly then you may be in violation of your probation, but if what you are saying is true then you should be able to have an attorney speak with your p.o. and make the necessary arrangements or changes to your probation.