I had acne on my chin also & have been able to clear it up..... after 7 years on the bcp. Definitely don't go on it unless you exhaust all your other options. I was never able to clear my skin with just diet but I think the real factor that caused it was dieting & being underweight- within a year or two of going on The Zone diet I lost below 100 lbs and something shifted hormonally. I'm a hardgainer/ectomorph and admittedly, I didn't try real hard to gain weight, I just kind of kept on with my Zone meals. Your diet sounds good so what I would suggest is you have your hormones tested. A doctor or maybe some kind of endocrinologist specialist can help you, or if you can't find help, consider maybe doing a Life Extension blood panel though I don't know if they are international. I hope it all works out for you.