So I would really recommend the Dave McGuire course. They have an inexpensive self help book on Amazon called “Beyond Stammering: The Mcguire Program for getting good at the Sport of Speaking.” You can have the book downloaded onto your phone in minutes if you get the Amazon Kindle app. The book will go through psychological reasons for stuttering, give you a breathing technique, and inspire you to get out and practice speaking. The program will be fear inducing but use the people closest to you for support. Keep practicing the techniques and follow what the book says. Then I recommend reading “Redefining Stuttering” by John Harrison, someone who stuttered for many years and was part of the National Stuttering Association for many years. You can find a free link to the book if you google the title. If you can’t find it I will help send you a link. I was surprised to find the book for free after seeing it was sold out on Amazon. These resources should help you in any language you speak. It is common to stutter differently in different languages. I speak some Japanese and stutter more in Japanese than English. You probably just have had some negative experiences speaking Mandarin and you need to create many positive speaking experiences in Mandarin to overcome the negative ones. Let me know if you need any help!