What is the best way to make pimples go away, I wash my face twice a day and it still doesn't work?

Several options. Otc preparations like benzyl peroxide can be helpful. There are others as well. Most help dry and remove superficial skin. Perscription topical meds such as retinoids and stronger agents work as well. Sometimes your doctor can use topical or oral antibiotics, in low dose. There is Accutane which is useful but must be used with great caution. See your doctor. He/she can help.
See your Doc. The prior answer addresses medications, which is actually a complicated issue. I'd like to mention a few more general things. !) wash your face when it needs washing, and no more. If dirt was the problem you'd have had zits when you were 4yrs. Old. Soap and water will do fine. 2)it has nothing to do with what you eat. Eat well for your good health, but it's not chocolate, or pepperoni.