How can I improve my singing voice?

I've had a voice teacher for two years and she's very good and knows what she's doing but has me do all opera arias. She loves showtunes, I love showtunes, and she knows I'm a broadway girl but we've barely done anything like that, she just has me keep focusing on those stupid arias! My clical head voice is very well developed, (I'm a soprano) and I have almost a three octave range. I can't belt though and I can't ever get a nice clear tone with normal broadway songs without singing in my upper range. My problem with belting is that I can't get the right placement and I always end up pushing from my throat which hurts my voice. Can you please give me some belting tips and broadway singing tips? I really need some help.