It would be hard to see any significant abnormalities in the scans and tests you had, if it is something like costochonditis.
The general area where you are affected is consistent with costochonditis.
Look it up on Gray's Anatomy online to do your own comparison.
It's an inflammation of the area where the ribs connect with the cartridge which attaches them to the breastbone and usually gets diagnosed by physical examination and medical history..
The scans and tests you already had, help rule out a few other conditions, some of which could be a lot more serious or even life threatening.
And in saying that, I have no intention to downplay the level of your pain and suffering..
I, myself, had a couple bouts of pleurisy in the past, which was so painful and it made me scared to even breath, or change position!
A friend of mine had costochondritis and it seems it took forever to resolve (like almost a year).
She finally tried a 30% DMSO solution with water topical treatment a few times daily, for about a month , as I had suggested to her, before her condition improved.
Note that DMSO is not FDA approved for humans.
It is used for animals in farms, specially horses, for recovery from inflammation, muscle strain etc.with great success.
It must be applied on freshly and a thoroughly washed body! DMSO is a strong anti-oxidant and also a superior driver, which can drive impurities into the body almost immediately!
Can be purchased from Vets, Equestrian and farm supply stores or online.
I have been using it as a constitutional topical anti-inflammatory and pain remedy.
It freezes below 65 F.
I hope this helps, however, my comments are not intended to replace medical advice.