Is it new? Sounds like the internal gyro isn't working or the tail motor is burned out. Also, if that's the nimh battery you should really cycle it a few times before you get full power out of it. I'd personally ditch the stock battery and get a lipo.

I would also suggest that you never fly the heli in the house. Believe me, my wife throws a fit everytime I put a blade strike mark on the wall. If you need an indoor space then try the garage.