Anxiety often presents itself in the way you have described, negative imagination. A person with anxiety tends to ruminate like a cow chewing its cud, there is really no benefit of the thought other than the fact that it is there and it is on a loop until A: It happens, and we say, “See! I knew it all along” or B: We learn to let go of these negative thoughts and seeing them for what they are- Our imaginations run a muck. In a way it is OCD because of the loop, I’m not a psychologist so I don’t know, but it seems people can definitely become obsessed with negative thinking. A beneficial book with good tips on over coming this problem is Dr. Abraham Lowe’s “Mental Health Through Will Training.” I have also read many other good books from non-doctors spiritual leaders, but Dr. Lowe’s technique works very well and presents strategies for overcoming the problems presented. There are ton’s of positive self help gurus out there that you can listen to or read, in my opinion (I have listened to a lot of them) Napoleon Hill is maybe the greatest and I would recommend you listen to “Napoleon Hill in His Own Voice: Rare Recordings of his Lectures.” The self-help book selection is an endless sea of recycled ideas, Napoleon Hill was an original, and sometimes you can find gems. “The Energy Bus” by Jon Gordon is also gave me some needed optimism. Like anything though, self-help books can become temperary band-aides until we unconcsiously forget about them and what they say which is why Dr. Lowe’s book is good it is psychologically based in order to instill a person with the tools they need to maintain their mental health.