>I would like to know if C++ is actually used in games development...
Yes, C++ is used in game development. That's actually an understatement since C++ is the de facto standard language for game development. Most modern games are written almost exclusively in C++.
>so this implies i've selected a worthwhile career.
If you have the drive for it. Game programmers are a determined lot. They work very hard for long hours and constantly study new technologies and techniques. You also have to do this to be competitive. Game development is a rough field.
>By the way, is it possible for say or 6 programmers get together and write heir own game engine?
Of course. It's harder to coordinate and work with a team though.