How do i improve?

How do i improve? i have had a stutter all of my life. i’ve gone to plenty of speech therapists and none have helped in the long run. my problem with stuttering is the general repeating letters (c-c-c-) and i have a hard time saying certain words (word block). this has been a problem in almost all of my conversations i have and it greatly affects my overall life. does anyone have any tips or tricks they use to try and “overcome” this?