It would be really useful, perhaps, to know a bit more about your acne and what characteristics it has. (oily, dry, scaly skin? Red, white, black heads< face, body? How long you had it for? What treatments you tried? Had any results with anything?
However.....
at the end of the day you will probably end up trying several things until you find something that works. For me that was high dose oral Vitamin B3 (called niacinamide or nicotinamide). This is not chemical or pharmacological, which seems important for you. I can't promise this will work for you ... but it is cheap, safe, no side effects and if it's going to work for you you will see it improve very quickly. You can read more info at [Edited link out] and other places on the internet.
Happy to give you more info advice if you can get back with some more info.
Cheers!