I wasn't born with speach difficulties, nor I had any stuttering issues during my childhood, so I don't know if my experience can be helpful for you, but I still want to share it. I developed a stutter around the age of 17-18 due to severe depression and low high esteem. In context, my mother was alcoholic, we were very poor and at the age of 17 I had to change school where most of the kids were rich. Although I wasn't mocked or bullied for my social status, I still felt very inferior to others and that started affecting my speech,out of the blue I had stuttering. Unfortunately , that problem followed me for the next 15 or so years,it became worse and worse and it cost me a lot, both personally and professionally. Until few years ago when I changed country, job and most importantly my lifestyle. I hit the gym, developed good physique, started dressing nicely, my self esteem gradually skyrocketed and without realising it I stuttered less and less. As of today, I don't stutter at all and I'm very happy about it. In nutshel, my stutter was caused by depression and low self esteem, I fixed those and the stutter dissappeared. I hope my experience helps you.