Can I really become a professional in the game and film industry?

As you've already seen, there is enormous crossover between the two industries. In the future, there will be no difference between the 3D assets used in the film and the game spin-off. Gamers will walk around the same sets that were used in the film, simply because the film sets will be entirely digital assets. This also means that the bar for entry into the film industry is lowered significantly. If you are a skilful SketchUp asset creator, you will be able to create a set for a fraction of the cost of the real thing. This means as long as you can afford a couple of actors and a blue screen setup, you're well away to being an Indie Film Director. Okay, that's simplifying it too much. It may take a larger team than just you to create a full-length film, but there's no reason why you can't be a spoke in a bigger wheel, or even the hub itself.