This is a great photograph from a composition standpoint, but it lacks the tonal range to make a dramatic black and white photograph. Most of your tones are in the ‘grey” mid-tone area. You have almost no black or white tones in this photograph. I’ve attached your “levels” reading below so you can see that your pixels are bunched up in the middle-tone region. To the right is the white tones and the left is the black tones. Notice how you lack pixels in those areas. The height of each bar represents the number of pixels in that tone. Notice how the bulge in the middle represents a vast number of mid-tones.
You probably interpreted your dark grays and black and your light greys as white, but as you can see by your reading, there are virtually no blacks or whites in this photograph. Black and white photography is not easy because we are not used to seeing in tones and a light grey tone can easily be mistaken for white. Not only that but finding tonal range in our everyday environment is strangely difficult.
One trick you might want to consider is playing with your exposure levels. For example if you find a shot with lots of white but the dark isn’t quite dark enough, you might be able to underexpose the shot to pull the dark greys into the black tones without loosing the brilliance of the white.
But from a composition standpoint, you’ve done a great job. Just keep your eye out on those tones.