Dry dace, lip, chin, taking cetaphil, vaseline. What is wrong?

I have been getting dryness in parts of my face from the lower lip , chin and now both sides of my chin. I m experiencing this every morning which started autumn last year. I was given cetaphil which I use daily. However, cetaphil only helps for a few minutes and those parts get dry again. I used vaseline which helped me a lot but aggravated my dust allergies. I tried using natural oils like sweet almond oil combined with calendula oil and it s still not working. I ve seen a dematologist before but she doesn t seem to know what to do with me and has prescribed expensive lotions, like Exomega to treat this problem. What could possibly be wrong?