The thing about composition is that coming up with a bunch of bad ones is COMPLETELY normal.  Sometimes you get the right one in 4 thumbnails, sometimes it’s 40.  I’ve had an instructor talk about the time he did about 120, and after taking a good hard look at them all, he went back and used the 3rd one. 

Also, look at tutorials on storyboarding.  Those usually have some pretty stellar tips on composition and staging.  And in the case of compositions from observation, remember that you don’t have to put in everything you see.  Design the scene.  Louie Del Carmen and Kevin Dart are great artists to look at as far as that. There is also the book “Framed Ink” on amazon, which has a lot of great info on composition, staging, lighting, camera direction, etc. 

As for your style being all over the place, that is completely and totally normal, albeit frustrating.  Everyone has been there at some point or another.  Continue practicing from life and immersing yourself in the art you love and it will come, I promise.  :)