Is it people you know or people you don't know or both? Maybe try and say 'I have a stammer' if their reaction is off, will often relax the situation! I'm not sure where you live but there is stammering support groups, know here in the U.K. there's one in most cities/areas! Even speech therapy through the NHS, when I was younger it made me feel better going to those because I didn't feel isolated with my speech!