You know, in reality no one really cares that you stutter and the sooner you understand it the sooner you you'll feel better. I've been stuttering for 13 years (I'm 17 currently) and it still isn't gone but it was drastically reduced comparing it to for example 4 years ago. You just have to stop caring and thinking about it and force yourself out of that box you've made. For example when your friends wanna hang out or voice chat online or the teacher in school asks you to read something you have to force yourself to do it. I guarantee you it will reduce your stuttering a lot. Staying home and talking to nobody other than your parents/siblings (like I did for 2-3 years) won't do you any good, it will only just make it worse.