Jawline and back acne

Very strange. I had acne as a teen, but I’m 25 and haven’t had acne hardly at all for the last 5-6 years. This year, I suddenly have it all over again, but my main issue is jawline, chin, and back acne (occasionally very small bumps on my chest too). It’s usually bigger, painful zits… and of course terrible looking. Seems to happen almost ALL the time. I have rare times during the month where my skin clears and I have zero acne, but it lasts about a max of five days… I can’t figure out what’s causing it because I haven’t changed anything significant in the last year or so. I’m not on new meds, birth control, diets, etc.

any suggestions?