What is wrong with the Lewis structure depicted below?
Firstly, it's very apparent that the formal charges are not minimized here -- the oxygen has a formal charge of +2, while the carbon has a -2. Hence, this structure is very unlikely to occur, and would be very unstable if it did.
Secondly, it's a rule of thumb to always have the least electronegative element in the center (never Hydrogen). Oxygen is more electronegative than carbon, so having it in the center violates this rule.
The best Lewis structure would be achieved by simply switching the carbon and oxygen atoms.
Hope that helps :)