Anxiety plays a huge part in it. I rarely stutter with friends or family who are already aware of my stutter. Building your confidence helps alot, i found that letting someone know beforehand makes it abit easier for me to talk withiut the fear if them finding out. But it gets easier with experience, exposure therapy is good, purposely put yourself in social situations and pay attention to what triggers ot, for me its the start of certain words and sounds, so ive started substituting words so things are easier said, hope abit of insight helps, i know how it feels to not know what to do and feel hopeless but you'll be aight man