Accutane Cummulative Dose.

Okay so, I had a full round of accutane for cystic acne around five years ago. My acne came back and I’m now on month 4 of my second round. Does my last treatment count towards my cumulative dose, or has too much time passed since then for it to be effective? I’m just worried and trying to make the most out of this treatment. I have also lost weight during my treatment, so should I be worried about hitting my dosage that way? I started at 200 pounds now I’m at 180, and I’ve taken 60mg a day.