Hi, if all of your tests are normal! I am sure this is psychosomatic! Why don’t you visit a psychiatrist? No shame in trying? I have had this problem for two months and i discussed with my psychiatrist who explained it to me that it has become sort of an OCD! I am on meds, just started them! I think they have helped a bit so far! At least I don’t panic no more, and dont frequently gasp or urge for deeper breaths but it takes time!!!! It is a habit that our body has started and to break it, i at least needed meds! M not sure if it is the complete cure but i do feel a bit better! You need to trust yourself, the meds and be hopeful! I still have days where i have urges and since these urges grow when we think about it, it means it is psychological! If it were organic, it wouldn’t even let you sleep a bit! This is my piece of advice to go to a psychiatrist!