[INeedCoffee]

As someone who, myself, has very scattered speech and thoughts and yet still has to be able to speak in front of others for many reasons, I would say that the best thing you can do is to practice what's called "extemporaneous speaking." The literal definition is just "speaking done without preparation," but, as I learned from one of my prof's in college, it's more than that. You have a rough outline prepared, even some stories, maybe opening or closing points. Then, think about the kind of questions you might get asked. Don't prepare for individual questions, but prepare answers that could fit multiple answers with a bit of tweaking on the fly. Having a solid idea of where you're going is key. Admittedly, I still have trouble with this too, but I have far less than I used to. I wish you all the best!