I would try the breathing technique that I use. I’m not sure if there is a “proper” name for it but I would only speak on the exhale. How I do it is: Take in a deep breath, and as you’re breathing out then start to talk (inhale, exhale then speak), now in the beginning you will know when talking to people it will always be some sort of delay when responding to people, which is fine but as you continue to work on it your speed will pick up and later on as soon as you take in a deep breath and immediately exhale you can speak immediately and have fluency. I hope this helps