I apologize for what I'm gonna say because I know this isn't what you wanna read but putting yourself in the fire is, in my experience, the best thing you can do. Being a waiter, my stuttering dramatically reduced and I gain a shit ton of confidence, this morning I did a great phone call without stuttering at all. It does work but its hard and it aint magical, you will still stutter, but it will be hella better than now, trust me