TM, feel better!
I get mouth sores just before I catch a cold. Even before I get the sore throat part. I swallow tons of L-lysine and Airborne, every 4 hrs. Yes, stress can wear you down. Now that you know you have a cold, you can take action to prevent it next time. Something in your body is not fighting viruses very well. You need to increase your white count, sleep, sleep, sleep, and maybe give up tomatoes and other acidic items for a while.
I'm sending a warm compress and hugs through the computer ...