I took Accutane many years ago. I remember using a lip moisturizer from one of the major cosmetic lines... the kind of thing they sell to older women with dry skin. I really like Philosophy's "Hope in a Tube" for eyes/lips. You could also try Neutrogena "Norwegian Formula" hand cream. You can put it on your lips. Let it soak in and top it off with Vaseline lip stuff to seal it in.
Drink lots of water and don't pick at it. It will get better I promise.
Actually, Philosophy's cleanser "purity" is really amazing too. Very gentle, won't overdry your skin - which makes it crank up the oil production. Worth checking out... most places that carry Philosophy will give you samples. Also popular on Ebay.