To all the deferrees:
Your level of confidence at this stage is irrelevant. If you were competing in an athletic contest and did not succeed in the early stages of the match or game, well in that case confidence would be important because it would affect your performance for the rest of the contest.
But in this case all you can do are administrative things such as reconfirming your interest and updating your application with any notable new achievements. And of course you want to make sure your first semester grades hold up, but you would be doing that anyway to bolster all your applications.
So I would suggest not to get mired in a negative confidence trap. Use that energy in a positive direction to nail your other applications. Your level of confidence or lack thereof will have zero impact on your chances at Brown for RD. And, as someone not affiliated with Admissions, it is my opinion that your chances are fully alive in RD.