thank you for your query
drinking water with lemon slices in it is a good habit.don't worry that is not the cause of your skin drying up.
if the dryness is severe i can suggest few tips you can follow..
1.Use non detergent, neutral-pH products to cleanse your skin. Avoid using any commercial soap. And always touch your face gently.
2.Follow a bath or a shower with a mild application of baby oil.
your face with home-made nourishing cream every night before sleeping
4.once a week you can have full body application of aloe vera
infused oil/moisturizer.and wash it off after half hour
this routine should restore the supplenes of your skin in 2 weeks time.
thank you ,
wishing you good health