I know it's difficult being assertive. I'm usually quite a strong person but when I go in front of my Neuro I come across as being a wet lettuce lol. I think a lot of it stems from just nerves. You get so anxious and desperate for a resolution to your health issues that it affects your assertiveness. Just keep in the back of your mind that you're ultimately responsible for your health and communication of your medical history and you've got to get this sorted once and for all.

If it helps, maybe you can ask a friend to go along with you as support?