Thanks for the feedback!
This kind of lesion in the mouth can occur following an episode of illness, stress, fatigue, consumption of an irritating food or irritation with an object (utensil, toothbrush, etc.) but usually goes away on its own.
What you can do on your side is to use a soft wire toothbrush, and favor an alcohol-free mouthwash if you use one, avoid spicy or irritating foods. You can continue gargling with salt water if you find it helps, just avoid rubbing the sores as much as possible.
A paste like Orabase can help reduce irritation when you eat, and does not require a prescription.
Tylenol and lozenges can help relieve throat irritation, and I encourage you to drink plenty of fluids, cold or hot depending on your preference.
I hope this helps, and I am available if you have any further questions!
Tom Samaha, pharmacist