That's great for you. How severe was your stutter? My guess is that having a slight stutter is easy to technique against, but the more severe it gets, the harder it is to use techniques, especially one like singing/rapping. Some people, (like myself up until a year a go), in some situations find it very hard to speak at all. It's not as easy for people like this. The "just do it" mentality isn't enough to "cure" a stutter. It cannot be cured.