If anyone remotely understands, I do - I am a composer. I think my proposal is quite good, but I feel like I sucked it up on the interview and have been driving myself mad thinking about it. At the end of the day, it all boils down to their agenda and if your proposal works with what they want.
I have done well with a few things and have won a few competitions, but I don't have a ton to show for mine either. I know several other composers who have a deep repository of awards, fellowships, etc. I'm getting my DMA and will complete it next month. I have some of the exact same concerns about what I will do after. Hey - maybe I can write you a piece and we can vent all this frustration out with it? :-) Know that my heart goes out to you, for whatever that's worth!