My stutter is genetic and it is really bad, I block/repeat/elongate sounds multiple times per sentence. It probably has improved over the years but I personally cannot tell at all. I understand where you're coming from and this is really painful but you can't let it consume you. I am really proud of all my accomplishments and it's all because I didn't let my stutter stop me from living. I could easily give in to it which I've done in the past but I just got tired of hiding and when I accepted that this is just how I have got to navigate life, I have been much more happier and confident, focusing on my academic competence versus my verbal which we both know is fucked. No matter what, you just have to live and thrive in spite of your stutter.