Hi.. Welcome to HEALTHCARE MAGIC.. So sorry to hear about your problem and will try my level best to resolve it.. As per your complain it seems that red splotches over the tongue with a history of having Sjogrens Syndrome indicates that you either have atrophy or thinning of tongue mucosa along with inflammation and red patches.. It can also be due to a condition known as Geographic tongue in which there is formation of smooth red patches over the tongue.. I would suggest you to consult an Oral Physician or an Oral Pathologist and get evaluated and a thorough clinical evaluation and investigations like microscopic examination of scraping from the tongue can help in diagnosis and treatment can be done accordingly.. For Dry mouth you can start gargling with specialized mouthwash like Biotene and avoid regular mouthwash.. You should chew sugar free chewing gum.. Drink plenty of water.. Instil artificial saliva drops... Hope this information helps.. Regards..