I don't stutter when I talk to myself

I don't stutter when I talk to myself I'm 23M and a stutterer since my childhood. But when I'm alone and I speak to myself or reading a book out loud I don't stutter at all. For me It only happens when I'm talking to someone and really pisses me off. I also suffer from mild social anxiety and lack of self confidence. Is this normal and other stutterers are like this too?