Georgie,
Hi. You don't mention how long these white areas have been present. If less than 2 weeks and you notice that they are getting better, they may be ulcers caused by a virus. Typically, apthous ulcers will go away, even if left untreated, in 10 to 14 days. They appear as white, slightly concave, areas sometimes with a slightly red border.
These ulcers usually occur when a person's resistance is low, i.e., when they coming down with a "cold". So it is common to have other cold symptoms, such as swallowing problems and dry mouth. They can be quite painful and many times they occur in clusters of 2 or more.
I suggest that you see a dentist as a diagnosis cannot be made on the phone (or over the internet). I hope that this is what you are experiencing and as soon as you find out, let us know. I'm sure that you will no longer use tobacco after this experience.
If the diagnos is apthous ulcers, I will be glad to tell you what you can do to help prevent another breakout. It works for me and hundreds of my patients.
Good luck.
Jerry