Thank you for this very valuable question. Truth be told, it could be any number of things. Like you’ve already mentioned, it could very well be the wrong product for your skin. It could be that your skin’s barrier is impaired and it can therefore not retain moisture adequately (if this is the case you need a barrier repairing moisturiser). It could be that your have a hormone imbalance which can result in dryness of the skin. There are a few possibilities. In MOST cases, it is as a result of an impaired barrier, or the use of the incorrect products for your skin.