What makes you nervous? Maybe it's because there wasn't so much pressure to speak eloquently in high school as there is in the working world. There was more pressure for me in high school than in the working world, kids made fun of me and I made very little friends there. Try to invest some time in looking for speech therapy. In my experience in a corporate environment, my manager was patient and understanding of me even though I never stammered often. The more I interacted with co-workers and higher-ups during breaks and meetings the less I stammered overtime.