Turn it around.
There's no way to do it in OFP to the best of my knowledge. Your joystick software might let you. Better to just get used to it though, that's how helos are flown.
Basically, pull is 'up' push is 'down'. It's actually far more intuitive than an aircraft, it just doesn't do what you might think a throttle
would do, if you're used to other types of vehicles.