My apologies. I didn't look to see that you posted this in the "450 Heli" section.
Rc Helicopters can be pretty tricky to hover in one location...especially a 450 sized heli....especially at some serious altitude. Ya see...a good helicopter hover relies alot on the skills of the pilot. 450's are a bit twitchy to begin with. You have to see that the helicopter is holding at a particular location, then you have to see that the heli is being acted on by the wind (for example) then you have to be able to quickly, and yet gently, give the appropriate counter input to keep the heli in the position that you want. Helicopters, even full scale helicopters, will have a natural tendency to want to wander. It's just the "nature of the beast."
I have to give you alot of credit for taking your 450 heli up to 150 feet and trying to hold it steady. I imagine it will just take alot of practice to get the results that you want.
I probably haven't been a whole lot of help, but I wanted to try. Hopefully your heli survived the fall, with minimal damage and hopefully you can try again. Maybe practice at lower altitudes...50-100' and work your way up. It's gonna be a real chore to see your 450 at that height and then to be able to react to what the heli is doing in order to keep it where you want it.
Good luck!!!