I throw side arm, any way to help stop it?

Any ways to break my habit? My coaches are going insane not figuring out why I don't just throw better in 5 minutes -_- I throw fine when I'm close to a person warming up, but if i'm throwing from the outfeild, I completly side it, but its still straight as in arrow when I do it. I'm been side arming for almost 2 years now.