I'll try and hit this up again later to offer some ideas when my brain isn't so fuzzy from the cough syrup.
In the meantime - I just wanted to offer hugs - and please know that it isn't 'just you'. I worked full time and now substitute at an inner city daycare, and it took nearly a year for me to start getting any sort of authority with the preschoolers. Does your school have a lot of turnover? I know that's a pretty big problem with the center that I work at.
One thing that worked for me well was making sure to go out of my way to mention it to the parents or send a note home when a challenging kid has had a really good day - making a big deal out of it so they are more likely to do it again.
