Need help with glider system

Hello

so basically im trying to make a glider system like i showed in the video below (the game is airship assault) and im having problems with the turning part, basically i have this system already but it causes issues when you for example hold W and A to turn up an turn left, somehow the pitch goes all wrong and i dont know what the issue is, it is currently keybind based, any help or ideas on how to remake it would be appreciated, thanks!

Example:

My Current system:

bumping because this has confused me to all heck