Let's talk about speech specialists and how to choose one

Let's talk about speech specialists and how to choose one Hello everyone from Belarus! I sure almost no one knows what kind of country Im talking about, but let me know if you're from that 'land') I apologize in advance for my English, that's not my native and even not secondary language =) Here's my story. Some years ago I've started to learn programming and now its became successful. After short bootcamp I was invited in Czech company. I was so excited about it, so as it was very important for me as specialist. And now, in most significant part of my life I realize that I need to do something with my stutter. Every day I have a calls with partners and my colleagues and even when my mates says to me my speech isnt that bad, I see how it's hard for them to understand what I saying, my point, my view. Today I had a call with my boss to discuss my long-term future in that company. I was so nervous, so I fucked up, I couldnt even say a word, so my boss also did not get confused and tried to help me as he could. Dont get me wrong, it not that worried my colleagues as myself. Speech is the most important part in jobs like that. So I strongly decided to deal with my stutter. I had some experience with speech-specialists in my country, I was visiting it about 3 years and it didnt help me at all. Now I want to start visiting speech specialist again, can you guys give me some advises about how to choose speech specialist carefully? Note: Basically I have not that bad speech when I deal with my native language. But for now my only priority is English and it much more difficult for me to deal especcialy with it. Maybe you guys know why is that?