Hi there ~
I understand your concerns. I believe that if you are sexually inactive and have a canker sore
on your scrotum
it is due to poor genital hygiene. I also think that you might do well with consulting a physician for the genital hygiene and you should start consulting a local doctor who can help with your issues. I also think that there is no cause for alarm and you should be able to get back to being normal very soon. I hope this helps.
Take care and have a lovely day!