Proving them wrong

One of the things that I want to accomplish this year was a half marathon and hopefully a full marathon. The last few weeks since I started a new round of medication and injections all I hear from my Doctors and family is to NOT do this and how I shouldn't be running long distances. Apparently I am suppose to "listen to my disease." All I want to do is be successful at something while trying to prove to everyone else around me that i'm like everyone else and can do this! It's frustrating to be considered an outsider and all I want is to be "normal" (if there is such a thing). I want to be seen as a runner, someone who is successful and determined.