Yeah I can't seem to maintain a steady altitude, speed, or keep it from spinning. Oh well....
As said above - twist grip is essential in FS helo flying.
Basically :
Throttle = up & down (known as 'collective' in helos)
Joystick = direction as well as accelerating, slowing (pull back to slow down & using Throttle (collective) to control altitude)
Twist grip = to torque pedals (or rudder in fixed wing). This is mainly to control yaw. The rotor blades are revolving one way & naturally the body wants to revolve the other way.
Understand the basics, practice & helo flying becomes one of the best by far ways to have fun with FS

Simplicity is the ultimate sophistication. – Leonardo da Vinci