Developing a stutter at the age of 21?

Developing a stutter at the age of 21? I’ve never had speech issues before. I had some undiagnosed learning difficulties as a child that were never properly looked into but as far as I’m aware none of it pertained to speech. Recently I’ve developed a stutter and sometimes I get half a word out then it just fails. I can get my words out eventually and it usually doesn’t take that long. I would say this sort of thing happens at least once a conversation. I have no idea why this is. The only thing I can think is that I’ve been under extreme amounts of pressure and stress, and my anxieties are manifesting physically. Does anyone else have any experience with this?