Really dry skin around mouth?

Just a couple months ago, I started to notice that my area around my lips was getting dry. For the last two months I've had really dry skin around my lips. It gets really flaky and looks really weird. I have school like all day too, so i can't really do too much during that time. I used to lick my lips but ive stopped this last week and it still wont go away. I've used cocoa butter, aveeno, and different moisterizers including a type of chapstick. It helps for maybe a couple hours, but it gradually gets really flaky again. In the morning they look perfectly normal, but later in the day they start to become really dry. Is there anything I can do to cure this?