I grew up with a really bad stutter and went through 3-4 years of speech therapy. I suspect it could have been quicker if I worked harder (I was a young and dumb kid). My parents, one of which stutters really wanted to eliminate the issue from my life. Now it only comes up when I’m stressed. I highly recommend speech therapy if possible. If not there are books and websites that summarise the breathing techniques, relaxation and being mindful around ‘hard words’ - speak to a local speech pathologist/GP to get advice . Good luck!