3rd Month on Accutane 50mg But Still Severe Cysts Under Skin. Any suggestions?

I started accutane on 30mg for moderate acne and I weight about 76kg. After the first month i was having sever acne breakouts so my Dermatologist increased my dosage to 50mg/day. Now I am on 3rd month but i still have large (about half-inch) cysts deep under my skin. There are not at all visible but I feel them when i touch my face They itch a lot. I was patient all this time but i am begining to loose hope that my face will clear.I want to know is Accutane Working on Me?.