So sorry for this experience, I have had the same thing with saying my name, it got so bad I had to change my first name to something I could say, people just don’t understand, if I was you and you meet with this person at your work, I would pull him aside and tell him you have a stammer, I am sure he will look at your differently then and this will take any anxiety away from you. I am very sensitive also, and some people have asked me my name and when I hesitate to answer they have said , have you forgotten who you are? How ignorant, but what can you do, we have to rise above them and keep going.