The main rotor drive shaft has slipped. This is a common occurrence on the Mini CP (among others) after a crash. You can fix it by holding the bottom and top of the drive shaft, and pushing them together.
As for your initial problem with going into 3d mode, your heli wasn't set up properly. This is one of the features of a simulator - everything is perfectly tuned and trimmed. Whether this is a feature or a curse depends on how you're feeling at the time.
To fix this, you need to get the heli properly set up. Some of this you can deal with in the Tx, as you can adjust the various curve to move the end and center points of around to compensate for the heli set up. But the less you have to do that, the better it will fly. There are lots of videos and tutorial on how to set up a CP heli. I l ike the stuff from rchelicopterfun.com, but that's not the only good choice.
Two notes:
Don't worry about blade balance if the props are in good shape,. The blades on heli's this small don't weigh enough to create a problem.
The throttle curve in 3d mode should be flat. A lot of people recommend a V shape, which is correct for fuel-powered helis but not electric. A fuel engine changes engine RPM depending on the load. So a flat curve would have a higher RPM with pitch values near 0, and you need to account for that. Electric motors only change RPM with input voltage, so that correction isn't needed, and you want the curve flat.
I could give you my Mini CP config, but it's meant for practicing scale flying rather than aerobatics, and is for the 6S not the 7E so the the switches would all be wrong.
Do not ask me questions via PM. Ask in the forums, where I'll answer if I can.
My remotely piloted vehicle ("drone") is a yacht.
