Same here man. Back flips were the first trick I learned. I tried Fronts last night for the first time and under rotated just about every single one. Most of the backslaps didn't hurt until the one I overshot and landed on my back just before flat, that fucking sucked.
I can't get the rotation around on fronts. Leaving the lip to do a front seems unnatural, like you have to work against the natural force on your body that is pushing you backwards.
Do you basically forward pressure/nollie off the lip, try to put your head between your legs and tuck your legs simultaneously? The closest I got was a slight backslap/backseat that I rode away from but certainly wasn't clean.
My name is Nicky, but you can call me Dre.