I'm not sure what his DOC is...... the opiates, benzos, and alcohol have physical withdrawal. Cocaine does not have the same thing. A person can "jones" for it VERY badly and yes....that is emotional. The problem with cocaine is that it really doesn't have a "withdrawal" component that adversely affects you physically - it's that your neuroreceptors (dopamine/seratonin) have gotten use to a certain standard and adjusted to the drug. The book Craving Ecstacy is really good in explaining the whole thing.
This is not a matter of tolerating a bad mood. I went through it with my husband who stopped using cocaine ..... yep....there were a lot of bad moods and because he didn't work a recovery program the bad moods lasted over 6 years. I finally couldn't stand it anymore. When I left he went back to cocaine. But....his bad moods drove me away....and besides that - they escalated to a whole lot more than a bad mood.
There is a reason that people that use drugs and unless they address the underlying reasons the matter of giving up a substance is beside the point.
What I had to look at inside myself was why I was attracted to a man that had to alter his consciousness to deal with life. Once I quit looking at why he did what he did and approach it from why I chose someone that medicated himself I really began to get somewhere.