It's interesting, like some others have said I feel more comfortable and whole when I'm wearing a diaper, not necessarily more confident or anything like that, but then again, I don't wear 24/7 and I don't always wear when I'm out and about either.
One thing that I have noticed though, is that after a few days of regression time and wearing, I'll feel like a new man, I'll be refreshed, recharged and ready to take on the world and my adult responsibilities. So, in a certain sense, I guess my diapers and regression time contribute to confidence somewhat; the comfort, security, joy and relaxation that being a baby and wearing diapers brings, leaves me feeling confident after the fact, not during, but after (as I said, during I'm much more safe and contented). This is one of the reasons why I like to regress before I have a big contract to work on or a school project, regressing and diapering up clears my mind, relives stress and then, when I tackle what's in front of me, I do so with gusto. Of course, I try to fit in some regression and diaper time every week, regardless of how my schedule is