Alcohol (and tobacco) are physical addictions. I quit them both without outside help. Crossdressing is mental. I wouldn't call it an addiction but it doesn't really matter what anyone calls it. If you really want to quit, it's a matter of will power. Remove the temptation and focus on other things.
That said, Alcohol and tobacco cause physical harm to your body so there's a legitimate reason to quit. Crossdressing does not so unless it is causing problems in your family or social life, there's no reason to quit other than just that you want to.
Bottom line - You can quit crossdressing if you really want to and it doesn't take pills or group therapy to do so. It's all in your mind.