Your comment that you may be experiencing an allergy has strong possibilities. I know that I respond to citrus fruits with painful pimples, and many people here and on other sites have discovered a definite correlation between their dairy consumption and their acne. Sensitivities and allergies often develop over time so not being allergic in the past has no bearing on today.
Of course, you want some immediate results. There are a couple of things you can try now that may help what you have, but you will still need to get to the cause of the problem, which I'm guessing is an allergic reaction to something in your diet. The skin is a reflection of the health of the body. You have a build up of toxins that have finally been directed to your facial skin. Clearing the toxic load is essential to achieve long-term results.
In the meantime, try the above suggestions that appeal to you. You may also try a cheap method that I have heard of that I, too plan to try. Use plain, preferably unpasteurized(or pro yogurt as a mask on dry skin until it dries, then rinse. The probiotics that inhabit the yogurt is absorbed in the skin, and may help to reduce the Acne causing bacteria. It is a natural detox, that can help your skin cope with the toxic overload you are dealing with. You can also use the yogurt as a full body treatment.