Don't give up bro. May I ask you how much have you been practicing daily? After reading and researching various self-therapies and motivational books for more than two months, I have finally started doing some simple routines daily for 30-60 mins before starting work. Changing speech habits is super hard because not only do we have to learn new patterns, we also have to actively unlearn the old ones that have been reinforcing for decades. That's why younger people have the most success. Anxiety is another factor that makes progress invisible. It sends our bodies into animal like state where we fall back to our most engrained habits, forgetting everything else. So yeah, my conclusion is that in order to make meaningful long-term progress, we need to practice every single day. Every tiny step of progress makes us more aware and less instinctual when it comes to speech. Yesterday, for the first time, I managed to actually apply a technique on an incoming block while talking to my mentor. I had practiced earlier so it was still fresh, but I know there's no way I will be able to do it again and do it habitually, without continuous work. So my tip to you and everyone is to channel our frustration and anxiety into persistent action. We need to be dedicated like martial art monks. Study your stutter, don't let it scare you into passivity, admit to yourself and others that you are dealing with a challenge that requires extreme dedication and follow through every day.