I get what you mean, but it is difficult to invest my self-confidence in a particular area of my life, even though I'd love to, given the fact I already invest a lot of time into going to the gym, and am excelling in my academics. The issue lies in the fact that my self-confidence, just like everyone else's, is dependent largely on how the unconscious brain works, and no matter how hard I try I will derive a large part of my confidence from my social/interpersonal relationships, and I'd argue this is the case for the overwhelming majority of people, and right now, I only have maybe 1-2 friends and have not had any success with dating. So as you can imagine I am quite unconfident socially and I have noticed that when I drink sufficiently large amounts, my stutter disappears and it is one of the few times in my life where I feel confident (the general inhibition lowering of alcohol of course contributes greatly to this).