Continue repeated low dosage every 1-1.5 years or try 1 high dosage course?

I stopped having acne ~12 years ago but it came back on my forehead (though not as bad) maybe 3-4 years ago. I ended up trying a course of low dosage (10g/day for 4 months) Accutane since I also wanted to eliminate my oily skin at the time. It worked great and my skin continued to not be oily for the next year. However, the oiliness/acne came back after and I ended up doing another 10mg/day low dose course but this time for 6 months. I was going to continue for longer but noticed my hair starting to fall out, at which point I decided to stop. Fast forward to now, its been 1 year or just over a year and the acne is coming back (skin still isn't oily though which is nice). I'm just wondering if I should try a high dosage course this time instead? I don't want to have repeated cycled of hair falling out and slowly recovering. Also, I'm surprised my acne keeps coming back since I thought adults weren't supposed to really have acne -- I just dont understand why I didn't have Acne at all for that 12 year period. I think my triggers might be dairy/sugar related but I can't be for certain. It was really nice while was on Accutane/the year after since I could just eat whatever I wanted but its too hard to resist temptations sometimes...