I have had breathing issues from magnesium deficiency, toxic mould exposure, hypothyroidism, iron deficiency anaemia. As you mention being electrocuted! you may find taking a good quality magnesium supplement may help.
Excerpt from the article - Do You Need More Magnesium? 10 Signs to Watch For...
"3. Do you experience a lot of stress in your life, or have you recently had a major medical procedure such as surgery?
Both physical and emotional stress can be a cause of magnesium deficiency.
Stress can be a cause of magnesium deficiency, and a lack of magnesium tends to magnify the stress reaction, worsening the problem. In studies, adrenaline and cortisol, byproducts of the “fight or flight” reaction associated with stress and anxiety, were associated with decreased magnesium.
Because stressful conditions require more magnesium use by the body, all such conditions may lead to deficiency, including both psychological and physical forms of stress such as surgery, burns, and chronic disease."
Hello~I can sure relate to your problem. For many many years, I have had that horrid shortness of breath, it feels like I can't take a satisfying one at times. I have seen numerous doctors about this, they all say the same thing, high anxiety and stress. I will say, that if I am enjoying what I am doing, then I don't notice it at all, but, let me get stressed or depressed, back it comes.
I know you don't want to hear this, but, I truly think it IS stress or anxiety related, being short of breath and having the symptoms you are having is a classic sign of it. All your tests are "normal" no doctor can help, so, that narrows it down to anxiety. Like I said, I know, I have had it and still do, and depression, etc, are the culprits.
I am surprised that the acupuncture and chiropractor didn't help, at least a little, both have helped me to a degree. Have you tried massage therapy. If you have the tight muscles, this could relax them and help open up the lungs, they are being compressed because your body is in a state of flight-or-fight, thus causing every muscle in your body to be tight.
I wish I had better answers for you, I know now frustrating this can be. I hope you get better soon.