I have same problem. When we read , talk and sing alone , we don't stutter because our mind is calm and there's no anxiety. The moment we speak to someone whether it's family, friends , Neighbors or work people, we go into flight or fight mode and start over thinking about what they will think about us. Social anxiety and avoidance is the biggest problem. It's all neurological developmental. My best bet is to speak to outsiders as much as possible to train yourself to be confident. I'm doing the same slowly. Or even try anti anxiety supplements that's natural..it can help in social gatherings