Alexander Shulgin (The chemist who 'rediscovered' MDMA) wrote about this in his book PIHKAL.
It's a brief paragraph about a student who did some work looking at synthesis routes to MDMA, he suffered from a stutter. When "Shura" spoke to him again some time later it emerged that he had used MDMA to treat his stutter and it was all but unnoticeable.
This doesn't mean it's a cure. In the right hands (psychiatrist, trained professional) I think it's quite likely to work well, but if you're just taking it an hoping I imagine it would be quite hit-and-miss.
If you're only taking a small amount as you say, and you know it to be of good quality, the only real risk is criminal prosecution. What a sad world we live in that people are denied this type of therapy.