I had the same issue and turned my messaging off on the mac also and for me its easiest just doing it from your phone. If you look on your phone and go to settings and then messages. THen go into your send and receive where it shows where your messages are being received at, you probably have both your phone number and icloud email ID there like I did.
You can link your ipad or mac to imessages by logging on with your icloud account email ID, and this is telling it to send to both your phone number and your icloud ID, so its going everywhere when you get a message. Delete the email ID off there so only your phone number is listed.