hello
use of tobacco may lead to various premalignant lesion and conditions including
leukoplakia ,
lichen planus, oral sub mucous fibrosis etc etc
as per your description , the chalky taste may by due to tobacco
so what i would suggest is that you pay a visit to your
dentist and get a complete oral examination done to find out the exact cause
in the mean while to reduce the symptoms i would suggest that you do the following
1.luke warm saline rinses 4-6 times daily
2.gum
astringent like oracep ,take a drop of the astringent on your clean index finger and apply to the affected site after every rinse
3.zinc ,vitamin(especially vitamin c ) and
folic acid supplements will be also useful
having said that i would also suggest that you stop using tobacco as it may lead to further complications
hope this helps