Found to what appears to be a bite?

My cat sushi is female Burmese/ siamese, 9 years old, spayed and about 8 lbs?

She is a healthy cat, eats well, normal waste and everything.

I found this bite or something that is right below her mouth. Im unsure if she bit herself or a bug bit her? It seems like it hurts her when tocuhed. Does this seem like a bute and does it look infected?

Im located in texas.

https://imgur.com/a/BWc1ZHv