Hello @Eden1919 I really feel for you in your situation.
I support the other suggestions here, there are some very insightful ideas that might help you manage your fears and feel heard.
If you can't remember what you want to say under stress, perhaps writing down the points you want to get across might help, or even write out all of what you want to say, and keep your own copy too for later reference.
When I have to undergo proceedures or whatever that I don't want to, but have to, I have learned to give myself a reward for having having subjected myself to the intrusions. Usually, when I know it's coming up, I do some thinking and looking for something that would give me a sense of comfort and well being, and have it sorted for when I come back from the proceedure/s. Doing the thinking about rewards also helps take my mind away from the bothersome thoughts.
You're clever, you know yourself, you're very kind and I'm thinking all sorts of good thoughts for you to get through this. 