A while ago Oprah and Dr. Oz did a show on quitting smoking - I finally sat down and looked at it - the power of DVRs. All the people in the audience were supposed to be smokers - imagine what that smelled like for a moment - UGH!!! Yuck! I wonder how many people quit smoking just because the room smelled so horrible? You know it's in their hair and clothes and mixed in with their colognes and perfumes.
Okay - that's not my point and now you know I am a non-smoker.
The people brought up the concept of grieving the addiction. That's something we have to deal with when we stop an addiction. How is life going to be without it? How are we going to be? Will we like ourselves? Will we miss it so much that we'll get depressed and not be able to function? Will we replace it with something else that can become detrimental to us - excessive food, for example. Knowing how we are grieving is a big clue into our personalities and if we listen to it we can be proactive in our journey. For example, if we fear replacing the drug with food, then we can plan around that; if we fear depression, we can be proactive to prevent it.
So go ahead and grieve. Listen to your clues. Write them down. Make plans to help yourself succeed.