A Black BG is not going to help this image. Your blacks in this case are just too black in the mid-section shadows for the black BG to work. An option when I am posting is perhaps to crop it real tight and then work your mid-tones down a bit (more toward the darker than light side on the tonal range.) As you can see by the new histogram, while the blacks are still overpowering the histogram, with the mid-tones brought more toward the middle and flattened a bit, the blacks are not nearly as overpowering - well, better anyway.
The second image I used from one I posted last night (Tetons Sunset which is a pure wash of bright light against the peaks with a mostly normal range of color throughout the foreground. The histogram reflects more of a push from left to mid, and right to mid. It could be argued there needs to a be a pure white and a pure black, but I think I'd argue that point vigorously. I use the histogram pretty aggressively when doing PP as a great checks and balances tool.
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As always, my opinions are just that and never meant to disparage or degrade anyone's work, but rather to either offer a possible solution or give an explanation based on my own experience.