CDing itself didn't give me confidence.
CDing AND going out en femme gave me confidence.
To me, the latter statement makes a lot more sense because you can potentially CD in the comfort of your own home, with no one judging you for your actions or the way you look, and the most you get out of it is the satisfaction you have with dressing up en femme.
Speaking from personal experience, I CD in order to unlock a lot of aspects of myself that I've denied myself access to over the course of the past few years, having a lot of confidence being one of them. I knew that by putting myself in a very unfamiliar situation that I will somehow gain the confidence to do anything that I wanted. I'm so proud of this that it's become a normal part of my life now.
You want to know how confident I got? Just a few minutes ago I was at a CVS shopping for makeup and I walked to the counter to pay for my things and, while the old lady who was helping me had this curious expression on her face because of my basket full of makeup, I just calmly looked at her direction as if I was buying a toothbrush or something else, paid for it, thanked her, then walked away. All this while I was en drab.