Hello from Texas Anders!
Welcome to the Academy!
Confidence is key. I think every musician/mixer/artist is to some extent self-conscious of their work, especially when putting it into a public forum. The Academy is a safe place to put up your mixes, and receive feedback without fear of ridicule. Most folks in here are super nice, but honest, and that is what we are all after is honest feedback so that we can improve. I am 45, and understand the doubt you speak of. We are fearless when we are young, but age brings with it caution from lessons learned. I say just grab one of the multi-tracks and give it a go, you won't be disappointed!