I truly feel for you, I completely understand how you feel. I am 20 and in college and it feels horrible to be passed over for internships in my field (Kinda computer sciency) because I don't convey confidence by giving a swift and snappy answer even if it's correct. I'm getting discouraged as well, for I too have been covert almost all my life, in the sense that i would let select people know I stutter, yet still substitute around them to not look stupid. I went to speech therapy for a while and the first thing the SLP said was to "Quit waiting or looking for a cure, the first step is to realize that you will be a stutterer forever and it is not something that will just go away". That hit me really hard, I didn't want to believe that, but a part of me feels like it is true. So for the longest time I would refuse to use the speech techniques because I felt like what kind of life would it be to have to constantly calculate my words and eliminate the spontaneity of my voice, so I went the no avoidance route like you have. The results have been sub-par. My confidence took a hit too as I realized that no matter how much I try to "be okay" with my stutter, the sinking feeling of victim hood and jealousy of fluent people never goes away. It gets tiring explaining yourself to others, enduring their ignorant looks, their impatience, don't even get me started on the initial stages of trying to make close friends. So I have come to the conclusion that perhaps I will have this forever, and it seems like you've reached that conclusion as well. I hope you can find something you can relate to in my story and take solace in the fact that you are not alone my friend.