I gave birth 2 months ago and since it is winter my skin on my face has gone very flaky...?

and i put moisturizer on my face but within half and hour its flaky again, my face is also very oily but it still fakes even though it's oily, it's starting to get very annoying and embarrassing as well please help me, i have been told to take some vitamins, does anyone know what ones to take?