please help

so these photos show my skin right now, compared to not even more than a MONTH ago... used to have super bad acne but it’s been pretty clear the past year, all of a sudden a month ago i got a face full of pimples OVERNIGHT, i kid you not within like 48 hours my face was full, plus my back, chest AND around my head has been covered, haven’t gone away the past month so not because of my period.. have been pretty stressed and crazy busy the past couple of months with school (exams coming up) and working plus sports a lot, maybe that could be why? just started a birth control (tri-cyclen) to help get rid of the acne.. any idea why this would happen that fast?

(no makeup on skin in this)