Yes I did the gym as well and I ended up in great shape LOL It will calm down remember its only been 4 weeks off alcohol and 3 three off the tram think how long you were using both its takes time to undo the damage in the brain .The exercise really does seed up that process because it helps restart your natural dopamine receptors.
Congratulations on your clean time! I am 3 weeks off of norcos, and I have been having similar feelings and thoughts. Sometimes, it just seems like my mind is thinking of the pills out of habit when I am in a situation, time or place where I used to use. Staying busy has worked the best for me, and I find that I am doing many of the things I enjoyed previous to my addiction. I try hitting the gym when I get a craving, and the bonus is that I'm getting back into great shape :) I spend more time doing my hobbies, etc. I think it gets easier with time (from what I've heard from others here).