Why do I have no results from Accutane 120mg a day for 6 months?

Hello, I’ve been on Accutane for over 5 months so far, I am currently over half way through my 6th month. The dosages were/are as follow: 40mg-80mg-80mg-80mg-120mg-120mg(currently). I’ve also been on prednisone (20mgs) twice throughout my Accutane course, it was 3 pills for 5 days, 2 pills for 5 days, and finally one pill a day for 5 days during month 4/6. The prednisone basically cleared my acne both time, but it always comes back. I am a 19 year old male weighing around 185lbs at 6’4. Jawline/under chin and forehead acne mostly/back/chest/arms acne.