There are some moments that may suck, but you need to go through them. My very first job was tutoring a kid by teaching him english. Of course I had my moments of real bad stuttering and the kid starring at me, the parents also being with a WTF face, and of course it was awkward, but I managed to just continue and do my job. After that I have had multiple jobs that required talking permanently, and of course there were awkward moments, too. But if you can do the job right, and specially if you bring any extra value of any sort, like an specific skill, the truth is that they don't even care that much.