I am so sorry.
Having a canker sore the size of a dime sucks. Also, the general sicky feeling that comes with it sucks... And the fact that nobody knows the difference between canker and cold sores and so people think I have an std, when I explain to them why I'm not eating.
A canker sore is caused (in my case) by having both b12 and iron deficiency (I've always been iron deficient, the b12 thing started last year) anemia, as well as eating a lot of acidic foods. Usually, this happens to me when I get a cut on my gums (like this time, a bit of popcorn sliced me), and then the acid just makes it worse and I end up with a canker sore.
This is just a chronic thing for me, but lately they've been getting bigger. Luckily, my mom is a dental hygienist, so I got some medication for it
But seriously. People. Learn what is and is not an std, otherwise you're just annoying when I have to explain this to you a thousand times. Canker sore is an ulcer. Cold sore is a puss-filled blister. The ulcer is inside your mouth and not contagious. The blister is contagious and is only on the outside. And no,
a canker sore is not "acid herpes" or whatever the muffin that is.