Problem with third-person camera (Please help)

I want to make a Third Person Shooter camera where the character’s gun, arms, and body points in the same direction as the camera, like in this video:


However, its turning out like this:

I used shift-lock, and its working when i move it horizontally, but it’s not working when i move it vertically. I tried using IK, but it wasn’t working so i just made an idle animation. Any help would be appreciated! I’ve already posted stuff similar to this with zero replies! Please help, as I’ve been having this problem for a long time!