The mind, your mind will sit you down and talk you out of and into anything if you let it. Comfort zones are where your mind wants you to live, where the excuses about why things didn't happen don't sit with you but with other people or events.
This goal you're chasing may not happen just yet, but it's better to try your best and give it everything rather than walk away from it just because the voice in your head says that you can't do it.
See what you've got. You might just surprise yourself.