Welcome to OCF. Im very sorry you are experiencing a mouth sore. Im sure it must be very uncomfortable.
I have removed the photo you posted. We simply are not qualified to give a diagnosis based on a photo so it does not need to be here. Please understand our group is made up of oral cancer patients/survivors and caregivers. We do not have years of schooling, medical backgrounds, or the patient with their full medical history in front of us. But, we do have knowledge we share from our own experiences and what others have gone thru as well.
Our saying around here is... If you have a sore in your mouth that does not heal on its own within 2-3 weeks then its time to get checked by a medical professional. I suggest seeking out an ENT who specializes in treating oral cancer patients. A biopsy may need to be done to find out exactly what the sore is. Your sore could have been there for a while and its likely to take a few weeks to get an appointment. I would suggest making an appointment with an ENT to get checked out.
As far as the use of a product that has been scientifically proven to be unbeneficial in healing, I suggest stop using it immediately. The FDA has found the risk of using silver products exceeds any unsubstantiated benefit. In fact, it can be harmful causing argyria (silver salts deposit in the skin, eyes, and internal organs, and the skin turns ashen-gray). Prior to purchasing any "healthy alternative" over the counter products first check to make sure they are safe. I did a search on Quachwatch and learned the silver you are using is not safe at all, it is a harmful substance that can cause you great harm. It could be making your sore even worse.
Quackwatch....