It depends on the person. I just finished a year long speech therapy course where I had 1 meeting a week with a speech therapist. Even though I saw improvement, it bothered me throughout the process how the emotional/mental side of things wasn't dealt with. Unfortunately, the past few months I got lazy and stopped practicing the techniques and I've pretty much lost all the progress I made with my speech. I don't say this to discourage you, just to make sure you don't expect a miracle from speech therapy. It helps and has helped people I know achieve fluency, but it is entirely dependent on how much effort you put into practicing and consistently pushing yourself to apply the strategies in progressively harder situations. Also, It's very important you're doing therapy for anxiety, that will help alot with the process. Good luck to you man and if you have any questions, although I'm not often on reddit, I'm available.