There are a couple of problems with this pic. some are within your control – others are not.
Firstly, what type of camera were you using?
If its a digital camera, its just not sharp enough, if its a scan from a negative, perhaps the scanning was poor.
Nonethless the sharpness (or lack of) lets it down big time.
Secondly – shooting directly into the sun is a very difficult art to master – I’ve been years trying!!
What happens is that the sunlight blows out the picture, and the shadows become black. There is no
detail in between too bright & too dark. This can be remedied by using graduated filters which block some of the light
out from the top of the picture allowing for detail in the shadow areas. You could also wait for the clouds to cover the sun, and you will still get a dramatic effect.
Finally, the cropping should be worked on. There is way to much sunlight in the top half and way too much black in the bottom half. I have cropped it to a landscape format (hope you don’t mind) so see what you think of this version. Unfortunately there is very little can be done for the overall lack of sharpness.
Hope you don’t think I’m being too negative, just throwing out a couple of pointers, and remember, if you like your photo thats really all that matters.