Your course sounds a lot like how mine went around that period, besides the improving part in the beginning haha. But around day 20 or so my acne was the worst it's been my entire life too, just hang in there!! I'm about to end month 3 and my face has improved greatly! I still have a lot of redness and some red marks from pre-existing acne since skin heals slower on this med, but it's part of the process.
If your acne starts flaring I would ask your derm about prednisone. It helped calm that nasty breakout I got big time in as little as a few days.
Best of luck!