I made a post a while back with a method I used which has helped me in the long run. My speech is very similar to yours, rapid speech, stammering on certain words and poor enunciation. Give this a read through, I think this should help if you stick to it. https://www.reddit.com/r/Stutter/comments/fbld9x/a_post_i_made_one_year_ago_an_unknownunderrated/?utm_medium=android_app&utm_source=share