This allows a few more thoughts and comments !
If that's your pants inseam preference, then I might suggest using 'cycling inseam' measurement - measurement more appropriate for considering frame size
Measuring cycling inseam use
use a sturdy book - at least 1.5 cm book spine, and barefoot...
would that put your overall height around 175cm + ?
your mention of SRAM doubletap seems to say you are looking for more 'modern' bike. There are differences in frame and how/which components will work on certain frames...
a bike/frame from the 20th century will be substantially different in workable components compared to a frame from the past 20 yrs (and more so for bikes 10 yrs and newer).
Given your flexibility which teamed with good core conditioning, will give you a much greater window on creating a 'position' on your bike, which is what 'fit' is all about.
SO given what you've noted - a 55 cm would be ok for a older frame (old steel/alu, maybe very early production CF).
A 54cm frame would be more preferable, especially if more modern design, with some riders even going to a 52 or 53... But 54 would put you in the middle of the design concept of most modern bikes, and also a real improvement over the 'older' designs - certainly for my 58+ yrs of riding performance bikes.
Given you have 58cm, I'd say very difficult to get a good 'fit/position' on...
Not knowing the finance elements, I would recommend selling/disposing the old bike, and looking for another more suitable bike, new or used.
As with all posts/info on BF, this is opinion - above is mine.
I think you can expect there will be others who present other points of view...
Keep your info coming, it goes a long way towards more directed conversation...
Ride On
Yuri