I have the exact same issue as you. Usually words that start with A E and H get me to stutter and when I know they will be coming in my speech the anxiety kicks in and I become focused on those words followed by an obvious stutter. I'm 30 btw. When I don't focus on it or am distracted by something those words just flow out. I try to use the distraction as method to get those words out. By this I mean breaking eye contact and focusing on something else or sometimes hitting my leg to get my brain distracted off the word.