Often, Acne is one of the ways the body tries to expel excessive toxins. I am not sure if you are eating a healthy diet. Consuming a lot of fried and or oily foods, etc can and do usually cause acne.
The other thing you need to do is to drink lots and lots of water. This is the best medium for the body to expel toxins in the system. You might also want to work on cleansing the systems and a good probiotics may be a very good way to start.
Finally, a sensible diet with lots of exercise, even walking is enough but do make sure that it is a vigorous exercise that can bring a sweat. I hope this helps.
Take care n hope you find relief from your Acne soon