L-lysine. Try a lysine gel cap pierce it and put the gel on your sore. Anti-viral creams like Denavir (penciclovir) can also be very useful.
Low acid diet. Avoid acids such as coffee, tea oj etc... Use mylanta or some other liquid antacid after you eat and before you go to bed. Take 1 tablespoon and swish it around for 1 minute and spit it out. Decreasing acidity in the mouth helps tremendously.
Salt water swish. Early on, you can try a salt water or hydrogen peroxide swish and spit. If the symptoms persist past a few days or recur frequently, see your dentist or doctor for an antimicrobial mouthwash, cortisone medication, or other solution.
Palliative Therapy. Canker sores can be best treated by learning what stimulates the canker sores and avoid them. Otc pain pills to specialized mouth rinses to prescription medications can be used to treat depending on severity.
Lasers. See your dentist for a laser treatment. That will expedite healing. A natural remedy would be to put coconut oil on it as often as possible throughout the day. It has anti viral properties, .
Symptomatically. Canker sores (aphthous stomatitis) are suspected to be an abnormal immune response but no one is certain of the cause. Treatments are aimed at relieving the symptoms and promoting healing. Topical steroid gels (by prescription) are helpful as are topical pain gels or washes. Otc products like mylanta or Benadryl (diphenhydramine) elixir used as a gargle may be of value.
How do you treat canker sores in your mouth that keep popping up every now and then, coincidently when there is a lot of stress or anxiety?
Prevention. Canker sore or more specifically aphthous ulcer can be prevented by avoiding a common foam detergent found in most toothpastes called sodium laurel sulfate. Switching to biotene or other toothpaste not containing this ingredient can be the cure in preventing this painful condition. During an episode, 2000 mg of lysine in divided doses per day can decrease the symptoms and time involved to heal.
Management... In your case, since you already know that stress is the triggering cause of your canker sore, you have no other option but to manage your anxiety and/or stress. Identify what is causing distress and do something about it. Seek help with a counselor or a psychologist or a church spiritual leader.