By telling them beforehand that you stutter. Or to make it feel even more natural, wait till you actually stutter on a word or when introducing your name, then instead of forcing through the stutter, take a lil pause and say something like >"Sorry, I couldn't get the words outright, I have a stutter. Just letting you guys know so so you're not confused or wondering why im like taking pauses sometimes when i talk hehe." By letting them know about your stutter, you already know that they won't come up with any other form of judgments in there mind since they already understood why you were getting blocks. Some feel fear and anxious because they try to hide their stutter and worry about others finding out about it. Some though, worry not because of others finding out that they stutter, but worry about what others MIGHT think of them(they may be mistaken as weird, awkward or socially inept, low self-esteem, or just that something is wrong with them). Letting them know about your stutter clears this confusion. Eventually the feeling of anxiety and fear should star to fade. After all, our emotions almost always resolve on the side of behavior and actions, because thats what we are actually doing, and not what were thinking. Just keep in mind that if youre not used to disclosing your stutter, the anxiety and fear will likely get more intense before it starts fading the first few times you do it. I can really relate to your struggles, hopefully this could help you in some way, good luck!!