Welcome to the forum, and thanks for writing your post.
I know when I go to the doctor or I talk to someone and I feel a bit uncomfortable, I take a list with me or write down what I want to say in point form. I may not need it but having a piece of paper , or notes on your phone, may help you feel more comfortable. If you feel ok you dont need to use your notes or you may use them a little or a lot.
These are some suggestions .
Also are you worried about your mum reacting in a certain?
If you want, let me know what you think ?