As others have mentioned, yes, this is a stutter. I have both. The repetition and the blocks. When I was a child, it was mainly repetition. Now I notice I block more often, but whenever I hear myself recorded, it's a mixture of both. I don't mean to assume, but have you heard yourself recorded (when not knowing you were recorded?). It's not until I do that I realise how bad my stutter can be especially considering it used to be much, much worse.