You are.
Btw. you do not need to know anything about coding, just apply common sense. You want to change camera.tilt? Then why not change it, the relevant part/ what you need to add has already been commented out:

camera.tilt = camera.tilt - 5 * mouse_force.y * time_step;
or
camera.tilt -= 5 * mouse_force.y * time_step;

You could or should clamp that value, too:

camera.tilt -= 5 * mouse_force.y * time_step;
camera.tilt = clamp(camera.tilt,-85,85); // you can try other values lower than 90, too
or
camera.tilt = clamp(camera.tilt-5 * mouse_force.y * time_step,-85,85);

Finally, player.tilt normally should remain unchanged in a movement code.

EDIT: Btw. your number of posts or the title below your name does not mean anything. If you want to create games don't expect that you get away with "I'm a newbie/ non-coder", that's bullsh*t, don't even start with it. Do what you are capable of, ask politely and PRECISELY what you don't know and what's crucial, learn from it. Do not keep a non-coder attitude, it will not bring you very far.