Welcome to HCM
We understand your concerns
I went through your description. I sincerely doubt when you said you underwent every therapy. For stammering
there is only one therapy, which is stammer therapy / stutter therapy. This includes behaviora therapy etc.
Every therapy needs something basic, change in the person undergoing therapy. The required change in you for stammer therapy is, your might. Never mind stammering. Stammering do look odd but people do know how to adjust with you. You should not become embarassed. Just imagine a person without legs adjusting with the crowd, he is embarassed but he is also bold. That is life.
Understand your stammering. Learn and analyze when and how and where it is coming. Prepare defence measures. Take action one by one using trial and error method. I am sure that you will not even need a therpist's intervention.
Hope this clears your doubts. Available for further clarification.