Pimples, oily, slightly dehydrated skin what can we do?

My daughter has acne, her skin is on the oily side, and dry too. She does have pimples, so she’s limited to certain types of moisturizers. We have tried EVERYTHING! Prescriptions, Proactiv, AcneFree, Clean and Clear, Neutrogena and more. Products that dry her skin out really help clear away those pimples, but when her skin gets too dried out, which doesn’t take much, her skin produces even more oil. We’ve tried facial scrubs, face masks, and dermatologists, but so far we haven’t found anything that can really help her skin, for both conditions. During ‘certain times of the month’, she breaks out more and produces more oil. She’s tried mineral powder to dry up the oil, but that’s just dries out the skin. When she doesn’t, her face gets oily, on a regular basis, and she’s embarrassed to even have pictures taken of her with the flash on (as her face gets shiny from the glare). We’ve really tried everything, but haven’t found a product or solution for botht eh pimples and oily skin. (I have a hunch that her skin is oily because it’s a little dry, and as I said above, oily moisturizers are not very helpful for the pimple problem) We’ve tried the oil free moisturizers though too, which instead start up a few new pimples. Does anyone here know what to do? How to help? Similar stories and/or successes? Thanks!