I'm coming back to you with my thoughts today regarding our problem. I think sharing and finding commonalities could help us find causes and treatments.
Things are going up and down for me. My opinion today (it can evolve of course) is that this problem is a mix of several elements, which is why the therapies I've done didn't succeed in curing it totally.
I think there is first a sort of vertigo due to a problem with eyes or internal ear or related to the body. This one is very "hardware" based. And then I think that based on this first sensation we felt someday, there is a psychologic phenomenon between phobia and OCD that put in our brain a fearfull thought that sky could suck us up. I think that confronted to this vertigo, the inconscious brain wrongly assumed that what we were feeling could actually happen. This is why I agree with you Daniel83 that this could be an OCD.
I think this process has been made possible by a previous state of anxiety and or stress and a certain type of personality (I am prone to obsessive thinking in general). When this problem occured for me, i was in a new job where I was having a lot of stress due to social phobia. It's like my brain had to much and did some sort of "burn out" in the form of this phobia/OCD.
What drives my opinion of the brain as a part of the problem and not only the body is that my phobia has quickly come to obsessive thinking. Hours, weeks and months after first feeling this, I was not only afraid of seeing the sky, but also by thinking about the sky, space or emptiness. Then came frightening thoughts about death, metaphysic questioning, doubts about other people and the world really existing or not (with feelings of derealization), impulse phobias (fear of having an impulsion to do harm to someone).
These other symptoms make me think that there is some relation with OCD. In my understanding, phobias are considered fears of a situation, but are fears of the thought of a situation phobias or obsessive thinking ? I found people talking about obsessive phobias for those kind of thoughts.
I've also noticed that I tend not to have this phobia when I dream, or just if I am close to waking up. It's like when I'm sleeping, the part of my brain which creats this phobia is sleeping too.
Something else is how much my general emotional state makes things better or worse. I know when I am to much under stress, fears come stronger and more frequent to a point where I am totally frightened. When I am in a more quiet period, things can be much better even if I have never been in a feeling that everything has totally vanished. Which is the state I am of course looking after. Not that everything is ok, but that these irrational and fearfull thoughts are gone.
I think Cognitive and Behavorial Therapy has helped make things more livable, perhaps I should have continue with this therapy but after 2 years, I wanted to try something else. I have done EMDR and can't see any results, perhaps small improvments. My new strategy is to work on being more confortable in my life, more secured, more quiet and relaxed. I've moved in another city and I'm looking for a new job (unemployment is generating anxiety for now). I try to practice sport and everything that could contribute to a healthier life. I'm working on my social anxiety and assertiveness to be more confortable with people, so that they are not a source of stress to me (which is perhaps the cause of all these problems)
I've stopped trying to much to find a solution because this had become obsessive and stressful too. I just keep informed from time to time and check the forum to see if I find new informations or testimonials. I think sharing is a good way to try and find causes and treatment. The similarities in symptoms between all of us makes it evident to me that we share a common problems that probably has common roots and solutions. Therefore, a consciencious comparison of our stories would be a good idea in my opinion. For example, like Daniel83, a big blue sky is more frightening to me that a cloudy sky, rain or snow. Perhaps because it looks more empty. I have a problem with big monuments too, zeppelin (but not really with planes, dont know why), ...
I hope this helps. Thanks for reading