Mountain Dew was "my crack" for a long time.
I couldn't stand the taste of Diet Mtn Dew. So I started mixing half regular with half diet. Then little by little, over the course of a couple weeks, I mixed more Diet to less regular. Pretty soon I was just drinking the straight Diet Mtn Dew.
Now I cannot stand the taste of regular Mtn Dew! So try that little trick. Mix your regular Coke with either Diet Coke or Coke Zero. It might work for you - did for me!