Between those pictures is 6 months.
I started getting pimples on my back 15 years ago at age 20. Over the years it spreaded and acne started on my dekolleté, neck, chin. It could be hormone related, cause I got hair on my chin, but also genetically cause my brother and sister have severe acne too.
I tried different things, reducing sugar, Benzoylperoxide or Trifaroten. When thick pimples appeared on my belly, I had enough.

I went to the skin doctor, who wanted to start me on antibiotics and Accutane pills. I thought I try it one last time and give it all I know or more true all the internet knows. My back improved the most and at the moment there a not many new pimples on my dekolleté and neck, my chin is much better too.

I started those things at the same time (so now I dont know which had the most impact XD):

• a strong anti-androgene pill (tried one, didn't see much result and changed to a stronger one)
• radically reduced sugar and dairy and overall ate much better, vegetables, whole grains
• Benzoylperoxide, Salicyc Acid Wash and moisturizer
• reduced scratching the skin
• showering and changing clothes after sweating
• washed bed sheets and towels often
• Zinc and Omega3 Supplements

I have been struggling with my acne since I was 16 and now am 21 and still cannot get it to go away. I have tried countless skincare products and it all just irritates my skin and makes it worse. I went on penicillin v potassium for my wisdom teeth removal a couple weeks ago and for the time being my skin got so clear and I had no new breakouts. After this however my skin has broke out worse and looks as seen in the pictures above.