Thanks for writing. I hope the tests go smoothly for you. I understand what you are saying. The experience I described with swine flu resulted in a pretty classic near death experience and a kind of existential detachment. I was 21, and honestly didn't know much about life or myself. I really didn't know how to live with the reality of my inevitable mortality. I can't say I've solved it, more like explored it/lived with it. My son-in-law has a very strong fear/dislike of death and he and my daughter and I have been attending a local Death Cafe--in a nice eatery where you can order lunch or a hot drink. This hasn't been a magic fix for him, but at least we're keeping him company, if that makes sense. There are as many approaches as there are people and I hope you can find a way to do more of what you want to do.

Your outlook on life sounds like depression talking.
If so, depression, can cause and even mimic many physical symptoms that largely arise from the brain, not the body.
I have experienced depression on and off my whole life which spurned a multitude of physical complaints, none of which were able to be diagnosed. I’ve come to the realization (along with my doctors) that this is psychogenic pain – essentially neuropathies within the body that that unfortunately replicate whatwe are all afraid of such as heart, disease, cancer, etc.
I hope you can find some relief.