Thanks for posting your query.Dry mouth
occurs due to decreased salivary flow into your mouth.
This can make your lips chapped,tongue feels thick.
Sore lips are usually associated with dry mouth.
Dry mouth can be due to the reaction of medicines you are taking in.
I would advice you to drink plenty of water and fluids to keep yourself nourished.
Salivary substitutes or sialogogoues can be administered since dry mouth can increase the risk of caries incidence.
Maintain oral hygiene
Get your teeth cleaned.
Visit your dentist
in every 6 months.