Whenever someone laughs or makes fun of my stutter i always react negatively back by saying something like "do you know what its like to stutter" and usually they feel humiliated. I always spin it around on them so they feel like the idiots. If they insult about not being able to do your job you then say "what am i not supposed to work!?" You should be proud because despite your stutter you keep pushing and work hard. You have every right to work and have the same opportunity as everyone else. Every day is a struggle for people like us in the work place but we gotta pay the bills some how. Keep your head up, and practice your speech techniques