My mouth looks crooked when I talk

Pimples on my inner lower lip?

Good evening, most people my age have beautiful, clear skin. I don't have the strongest acne either, or my whole face is not affected, but it is moderate. I have tried to avoid dairy products as much as possible, only eat oats, soy and almond milk, and drink a lot of water. Is it because I don't exercise enough? But thanks to good genes, I'm very thin. I know I'm talking a lot of nonsense here, but ... what could be causing my acne? A year ago I was at a doctor who prescribed a cream for me. She has for approx. 4 months my skin dried out so much that it was mostly free of pimples, but it did not fight the cause of the acne. What could i do? The dermatologist would probably only give me something again to fight my pimples, but not the cause. Also, since I changed my diet, I suddenly have great digestion problems.