You're so brave!

Why do people often tell me I'm brave? Is that a knee-jerk reaction to someone with cancer? I genuinely don't mean to dismiss anyone's comments if they are heartfelt, nor trivialize them, but I really want to know. I'm clearly scared all of the time to the point that it's taken over my life. Though many say being scared has nothing to do with bravery, how about the fact that so much of my day revolves around waiting for it to be late enough to justify getting high off sleeping pills? Is that something a brave person does? What is their definition of brave? Does it involve someone who needs to get high to feel better? Someone who stresses themselves out to the point they can no longer reason properly? Someone who rants daily on social media? Other people I know on Facebook have cancer. None of them rant about it. I'm the only one. How is that brave?