OP, the only advice I can give you is to get in contact with a speech language pathologist in your country. My guess is you do not reside in the United States. When I attend the National Stuttering Association’s yearly conference, I meet people from all over the world and I ask them do you stutter more or less in your native language. The average response is half are stuttering more in their native language and have are stuttering less in their native language when speaking another language. I met some who are the complete opposite to what I just described. As you know our brains controls our speech. What experts know is that stuttering is caused by the improper wiring in our brain. I speak a total of three languages. When speaking English, I am a severe stutter. It takes me minutes to say one sentence. My other two languages are Irish (Gaelic) and Japanese. In Japanese I am about 80% fluent speaking when speaking (not stuttering) and when I am speaking Irish, I do not stutter. It is crazy on how our brains works. Good luck OP, on finding the answer(s) you are seeking.