So I'm 15 years old and have very oily skin. It gets oily around noontime-afternoon and this is when I begin to breakout. I wash my face every morning and night as well as take Vitamin A, E, D, and Zinc. The vitamins have worked but the oil is still causing me to breakout in the middle of the day. I don't want to wash my face again or splash water on it because I heard that strips the natural oils and causes more sebum to be produced. What should I do? I don't just want oily skin for the rest of my teenage years.
I'm the same age as you and I'm probably oilier than you are. It takes around 2 hours after I put on my makeup for me to start greasing out. I'm going to go on Roaccutane since my breakouts are getting worse and I've tried pretty much every topical acne treatment to no avail.
I find that I'm a LOT oilier when I'm stressed out/in a bad mood. Perhaps this could also be making you oily? And instead of washing your face, you could try using blotting sheets (try finding sheets without any powder on them as this can clog your pores and contribute to even more acne). Urban Decay's DeSlick face mist did absolutely nothing for me, so I wouldn't recommend wasting your money on expensive topical products that claim to keep you matte. With skin as oily as ours, it's pretty futile. Try talking to a dermatologist about going on something oral. Hope I could help 
Eliminate insulin spiking foods. Try cutting grains from your diet completely for 1 month, and see how you feel/look (that means no bread, pasta, etc). Instead eat lots of protein and veggies.
It's good that you're supplementing. Try supplementing 1-2 grams of vitamin B5 which should reduce oiliness. Also make sure you're getting 50 mg zinc (picolinate best form of zinc). And also make sure you're supplementing probiotics: 80 billion units with several strains. And you'll also be needing your EFA omega 3's/6's; flaxseed oil with a blend of primrose/borage is ideal.
Lots more you can do, check out my thread if you want more info.
Best of luck!