You have to be comfortable in your own shoes. If it's not stuttering it'll be something else. The most perfect looking people have their demons and insecurities. You may assume the worst but people understand your issue so you don't need to give yourself a harder time than anyone else. They won't say it but after maybe a quick confusion, they get it and believe it or not are on your side. You can do all this stuff and not think twice about it. If you think twice about it, don't think three times about it. At 17, you've got more important things on your plate! Save the brooding for retirement! Keep moving forward!