I once heard a testimony of a guy on this subreddit. He stuttered and worked for a company. I don’t remember what the company sold, but he wasn’t in the sales department and was also afraid of taking promotions. But he said that he got an offer to partner with another company worker and make sales face to face with clients. He said that he was so afraid, but he took the offer, and at the end of the year they both received awards because they sold the most in the entire company! This sounds very similar to the situation you’re in. I heard another guy say on this subreddit that he once answered his front door and there was a solicitor selling something. The guy had a stutter but came across really confident! 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.