I already have quite good knowledge of C++. I've written 2d game in DirectX 9, played with network programming a bit and WinAPI. Now I would like to start learning 3D game programming and I wonder what would be the best approach? Should I learn DirectX 11 and try to create my own engine? I've already tried to learn DX 11 but it seems to be pointless... Going through DX 11 tutorials is a pain for 1 person and takes too much time in comparison to knowledge achieved. So maybe should I learn some 3D library like Ogre or download a game engine like Unity or Unreal? I would like to go with a solution that would give me most abilities and knowledge used in professional game development.
I would be very grateful if someone with experience could share his thoughts!