Part of the dryness may be hormonal but making sure you get half of your body weight in oz of water each day is really important. This means if you weigh 140 lbs, you need to drink 70 oz of water. I know that sounds like a lot, but remember that our bodies are made predominantly of water so it is crucial for our overall health and well being.
Another suggestion would be more EFAs in your diet. These are the essentail faty acids that our bodies need, Omega 3,6,and 9. Sources of EFAs would be avocado, fish(like salmon and halibut), walnuts, raw olive oil on your salad or steamed vegetables. You can google more food choices :)
Lastly, sometimes our hair and nails become brittle when we are not consuming enough protein. Assess your protein intake. If you don't think your eating at least 50 grams a day, you may want to increase.