Do you have someone you are comfortable with, that you can train to speak slowly with? For me it started when my son suddenly started stuttering (I stutter as well of course). A big part of his therapy is that me and his mom model a slower easy way of talking. So I do it 24/7 at home. I didn't even think of my own stuttering, but after a month or two I noticed my own stuttering decreasing. What takes time for me is to be comfortable enough to actually talk slower out in the world, and not just in the safety of our house. I really have to focus to be calm enough to talk slowly, as i'm usually stressed when talking for obvious reasons.