How do I slow down when I'm talking?

How do I slow down when I'm talking? Okay so this might sound weird to some people, but even when I'm typing - I miss words out and jump from one thing to another without realising its happened until it has (Basically rushing my typing causing me to have to re-read what I've typed constantl) For example I'll start typing a word and already be onto the next one without finishing the first one. This also happens when I speak alot of the time and I don't know how to control it. Its one of the causes to my stutter for a fact, but everytime I try to think about slowing down it makes me overthink how I say things and when I say things, making me one big mess. Does anyone have any suggestions to help me? I'm willing to try anything at all