I try not to over think things. I am just out of college and being in the work environment is interesting to say the least. I have my good days and bad days with my stutter. Put me on a spot in a meeting and I can be fully coherent, but go around a meeting table introducing ourselves and I can have trouble saying my name. If you know you are uncomfortable in a situation, just keep going at it. Eventually you will get used to being in that situation and hopefully get more comfortable. I use to just say "Hi" when picking up the phone because I knew "Hello, this is ___" would give me more trouble because of the length. I still have issues saying the full phrase but it’s not as bad. It will not solve it completely but it may help. Definitely stay calm and watch your breathing and just try to slow down your speech...even if it makes you sound weird but I find that it helps.