always read through the policies/rules/requirments for the show you would like to enter- find out how they keep the quilts (safe)...once you know how things are handled that should ease some of your anxiety.
many shows have separate catagories for hand and machine quilted, hand pieced, hand appliqued...there are many catagories- you may not have noticed...being 'self-taught' shouldn't have anything to do with it---more quilters are 'self-taught' than professionally taught--only a handful may have gone to college and majored in some sort of textile field...we all learn from each other- books- and alot of trial & error...so that's just searching for an excuse....and it doesnt' matter if you win anything or not---if you enter your projects to be judged you will receive wonderful knowledge...the judges write up a 'summary' of your quilt and the 'critique' can be a great learning tool...letting you know the great things about your quilt and the things that need some work- constructive criticism is a good thing- you can learn where you could improve & what you are doing right....sometimes you learn something totally new you had no idea was a step to take....so, stop feeling 'not good enough' and enter a quilt...you may find it is a very positive experience...and you will learn from the experience.