done4good - This is a normal response to existential fear(s).
Very true and you hit the point better than I could have (especially using the "drug" analogy). The existential crisis is a very common and normal and well-studied phenomenon found in atheists (and theists). Unfortunately, we have been conditioned to think that religion/God is the ONLY cure to the discomfort it brings. Had we been taught otherwise, we would be able to cope with the discomfort better, or not even have it at all. I think that the main reason we feel the discomfort is because we were taught/indoctrinated/acculturated to have only religion/God as a coping mechanism to a very common human brain-state. The more we want to live as close to reality as possible, the more we need good tools and coping mechanisms that are based on reality.
For what is worth, when I am in an existential crisis, I try to go "back-to-basics". I try to look inward and remember the basic and simple things that make me happy. I love hard work. I love learning something new. I love ice cream. I love good and crappy movies. I love my girlfriend. It's all good. Sometimes, when the world gets too big, all you can do is try to focus on the small things that make life worthwhile.