You really should consult with a criminal law attorney ASAP. If you admitted to hitting your wife, you really need to have legal counsel. Charges could still be brought against you. And whatever you do, don't speak with the police again. You are under no legal obligation to do so, even if they come to your house. As for your wife's sitution, she also needs immediate representation, if she has not already retained an attorney. Further, even if you do not want to proceed with the case against her, that's not your call. Only the state can bring charges so only the state can drop them. If there is sufficient enough evidence to move the case forward without your cooperation, the charges will not be dismissesd. Again, consult with a local lawyer.