Your siblings or parents don’t have to have a stutter for it to be genetic, for example, my Grandma’s brother has a stutter. So I know that somewhere down by bloodline one of my family members had one and I was just the who carried the gene. I also completely understand what you’re going through, it wasn’t until I was 14 that I was self aware of my stutter. It made me question everything that came out of my mouth; like is what I’m about to say necessary or do I not just say it. The best thing you can do is accept it and learn to love yourself.