I subconsciously eat paper towels

For some reason every time I use a serviette or paper towel to wipe my mouth, I end up chewing on it, the thing is, I’m not even conscious about it until someone points it out.

I’ll often only notice after I’ve swallowed half the square, once I’ve noticed I get really confused and spit it out.
I think it started as an anxiety thing, but now I do it all the time

It weirds out my family, friends and myself.
I’m not really sure what to think of it.