Should I consider quitting my Ph.D. after 6 months?
First of all, put aside your cum laude moniker. You are not in undergraduate anymore, you are in graduate school, and while you were miles ahead of your peers before, you now find yourself in a mix of your intellectual peers. This should be expected.
Second, there is no reason to be shy about raising your concerns in full disclosure to your advisor(s). The alternative is that you eventually leave anyway, so why not be brutally honest?
Your 'confusion' may stem from a lack of clear direction and path forward.  You can mitigate this by forcing yourself to write down you academic goals, and devise a plan to meet them, within reason given your advisors' interests and capabilities, of course.
Most of these things can be solved through communication; but unfortunately in higher academics communication can be difficult.
If you decide to go a different route, just make sure it is for your reasons and not those that are circumstantial.