When I read I never stutter

When I read I never stutter Why do I stutter only when I have to make words from thin air, but when I read, i am completely fluent? When I speak to people my words are getting extremely stuck, I don’t know what to do anymore and now stutter got even worse for some reason. I even tried psychedelics to restart my brain with no big results. Does reading out loud despite the fact that I am fluent that way helps me in any way to overcome stutter or I should do other exercises instead? What exercises help you most?