Wow. Really interesting to read through the comments.
I've had issues with acne since I was around 11-12 years old. The only time it wasn't an issue was during chemo when, literally, the chemicals were killing just about everything in my body.
Before you start treating, you really need to understand what kind of acne you have. There's acne vulgaris (most common, hence the name) which is generally topical and less severe than cystic acne (the kind I'm blessed with) which is deep, huge and painful.
Hormones are most likely the contributing factor at your age. Food appears to have no correlation to acne. It's simply caused by the body producing oil, bacteria and dirt being trapped by the oil in the pores and creating an infection.
http://www.mayoclinic.com/health/acne/DS00169/DSECTION=ca...
A visit to a dermatologist is probably the smartest thing you can do to find out what the cause is and what they recommend. In my case, I need to use a good cleanser and an Rx antibiotic. I've used oral antibiotics in the past, but as a cancer survivor, I prefer to address as needed instead of preventative.
OTC medications usually contain either 5%/10% benzoil peroxide or salicylic acid and can be effective. I have to use PersaGel daily to help prevent breakouts, but it doesn't always help. I also have a prescription for Duac (clindamycin - topical antibiotic) that I use when it's really bad.
Proactiv is basically a benzoil peroxide product, from what I can tell. Most of the recommendations you've received are NOT FDA-approved, so there's generally a limited clinical record of proof of effectiveness/safety outside of personal testimonials.
I use Kiehl's non-detergent foaming cleanser. It's been the most consistent for my oily skin. One dermatologist recommended Accutane, but I've worked for the company that manufactures it, and I'm not willing to take those risks with my medical history.
Good luck!