Why dont I stutter when I am reading out loud?

Why dont I stutter when I am reading out loud? My stutter is holding me back in almost every aspect of my life. One week ago I wanted to do something and change this. I start to read out loud every day for 30 minutes and I realize, **I do not stutter if I am totally relaxed**. If I think to myself while reading: *Uhh soon will be letter K: I have problems with K,* I will stutter with letter K 100%. When I dont think nothing, I dont stutter. My question is following: How can I learn to be relaxed during other things, like making a phone call or talking to strangers or even in job interviews... I want to be relaxed in this situations like 100% like I am while reading... If anyone experienced this please feel free to comment :)