When you flick your idle up on you can go inverted (upside down). When your hovering inverted at half stick, the more you slide your stick down (from half way) the more it opens the throttle and gives you more negative pitch, so when you are upside down your heli will climb. If your upright and in idle up and land on the ground and start to drop the throttle down, the heli will start to rev higher and you will force the blades to push down (not a good thing to do).

When you get to that stage, you really should find some help, even if you have to drive for three hours, it's well worth it.