I remember my first ever interview, I had the same problem. In the end, I got hired. I was talking to him many months later, "why would you even hire me, I could barely string a sentence together" and he explained to me that if somebody seems nervous or has some type of problem and they can still be open and are willing to put that effort in regardless, they'll also try at the job so he hires them. I have had a subsequent boss say the same.